Process for producing substantially amorphous propylene-based polymers

ABSTRACT

A process for producing substantially amorphous propylene (co)polymers, comprising contacting propylene optionally in the presence of one or more olefins under polymerization conditions with a catalyst system comprising: A) a half sandwich titanium complex wherein the cyclopentadienyl is substituted with one or two heterocyclic rings, according to formula (I): cf formula (I) in claim 1: wherein X is N or P; Z is C, Si or Ge; Y1 is an atom selected from the group consisting of NR7. O, PR7 or S; Y2 is selected from the group consisting of CR8 or Y1 and m is 0 or 1 and B) an activating cocatalyst. The above titanium complex and the ligand useful as intermediates in their synthesis are also described.

[0001] The present invention relates to a new high yield process forproducing substantially amorphous propylene-based polymers having highmolecular weights. The invention also relates to the novel class ofmetal complexes used in the above-mentioned process, as well as to theligands useful as intermediates in the synthesis of said metalcomplexes.

[0002] Metallocene compounds are well-known in the state of the art ascatalyst components in olefin polymerization reactions, in associationwith suitable cocatalysts, such as alumoxanes or aluminum derivatives.For instance, EP 0 129 368 discloses a catalyst system for thepolymerization of olefins comprising a bis-cyclopentadienyl coordinationcomplex with a transition metal, wherein the two cyclopentadienyl groupsmay be linked by a divalent bridging group, such as an ethylene or adimethylsilandiyl group.

[0003] Another class of polymerization catalysts known in the state ofthe art are the bridged cyclopentadienyl amido catalysts, which usuallyinclude monocyclopentadienyl titanium compounds activated by analumoxane or other suitable cocatalysts (see for instance EP 0 416 815and EP 0 420 436).

[0004] The international patent application WO 98/22486, in the name ofthe same Applicant, describes bridged and unbridged metallocenescomprising at least a coordinating group containing a six π electroncentral radical, directly coordinating a transition metal atom, to whichare associated one or more radicals containing at least one non carbonatom selected from B, N, O, Al, Si, P, S, Ga, Ge, As, Se, In, Sn, Sb andTe. Said metallocenes are useful as catalyst components for theproduction of polyethylene and polypropylene.

[0005] The international patent application WO 98/37106 describes apolymerization catalyst system comprising a catalytic complex formed byactivating a transition metal compound which comprises a group 13, 15 or16 heterocyclic fused cyclopentadienide ligand and a metal selected fromthe group consisting of Group 3-9 and 10 metals; said heterocyclic fusedcyclopentadienide ligand preferably contains, as endocyclic heteroatoms,one or more B, N, P, O, or S atoms.

[0006] The international patent application WO 99/24446, in the name ofthe same Applicant, describes bridged and unbridged metallocenescomprising at least a heterocyclic cyclopentadienyl group of one of thefollowing formulae:

[0007] wherein one of X or Y is a single bond, the other being O, S, NRor PR, R being hydrogen or an hydrocarbon group; R², R³ and R⁴ arehydrogen, halogen, -R, -OR, -OCOR, -SR, -NR₂ or -PR₂; a is 0-4. Thesemetallocenes may be used as catalyst components in the polymerization ofolefins, particularly in the production of homo and copolymers ofethylene.

[0008] The international applications WO 98/06727 and WO 98/06728describe respectively 3-heteroatom and 2-heteroatom substitutedcyclopentadienyl-containing metal complexes, useful as catalysts forolefin polymerization; more specifically, these complexes contain aheteroatom-Cp bond, respectively in the 3-position and 2-position of theCp, and are used for preparing ethylene/1-octene copolymers.

[0009] The Applicant has now unexpectedly found a new class ofmetallocene compounds useful as catalyst components in propylenepolymerization, able to produce high molecular weight substantiallyamorphous propylene (co)polymers in high yields.

[0010] An object of the present invention is a process for producingsubstantially amorphous propylene homopolymers or copolymers comprisingcontacting propylene, optionally in the presence of one or more olefinsselected from the group consisting of ethylene, alpha-olefins of formulaCH₂═CHR′ wherein R′ is a linear or branched C₂-C₁₀ alkyl or nonconjugate diolefins containing up to 20 carbon atoms, underpolymerization conditions with a catalyst system comprising:

[0011] A) a titanium complex of formula (I):

[0012] Wherein:

[0013] Ti is titanium;

[0014] X is a nitrogen or phosphorous atom;

[0015] Z is a C, Si or Ge atom; the groups R¹, equal to or differentfrom each other, are selected from the group consisting of hydrogen,linear or branched, saturated or unsaturated C₁-C₂₀ allyl, C₃-C₂₀cycloalkyl, C₆-C₂₀ aryl, C₇-C₂₀ allylaryl and C₇-C₂₀ arylalkyl radicaloptionally containing Si or heteroatoms belonging to groups 13 or 15-17of the Periodic Table of the Elements, or two R¹ groups form together aC₄-C₇ ring;

[0016] Y¹ is an atom selected from the group consisting of NR⁷, oxygen(O), PR⁷ or sulfur (S), wherein the group R⁷ is selected from the groupconsisting of linear or branched, saturated or unsaturated, C₁-C₂₀alkyl, C₆-C₂₀ aryl and C₇-C₂₀ arylalkyl radical;

[0017] the groups R² and R³ ,equal to or different from each other, areselected from the group consisting of hydrogen, halogen, -R, -OR, -OCOR,-OSO₂CF₃, -SR, -NR₂ and -PR₂, wherein

[0018] R is a linear or branched, saturated or unsaturated C₁-C₂₀ alkyl,C₃-C₂₀ cycloallyl, C₆-C₂₀ aryl, C₇-C₂₀ alkylaryl or C₇-C₂₀ arylalkylradical; two R can also form a saturated or unsaturated C₄-C₇ ring,preferably R is methyl, ethyl, n-propyl, isopropyl, n-butyl, t-butyl,phenyl, p-n-butyl-phenyl or benzyl radical, or R² and R³ form acondensed aromatic or aliphatic C₄-C₇ ring that can be substituted withone or more R⁹ groups wherein R⁹ is selected from the group consistingof halogen, -R, -OR, -OCOR, -OSO₂CF₃, -SR, -NR₂ and -PR₂, wherein R hasthe meaning reported above, or two vicinal R⁹ groups form together acondensed aromatic or aliphatic C₄-C₇ ring;

[0019] the groups R⁸, R⁴ and R⁵, equal to or different from each other,are selected from the group consisting of hydrogen, halogen, -R, -OR,-OCOR, -OSO₂CF₃, -SR, -NR₂ and -PR₂, wherein R has the meaning reportedabove, or R⁸ and R⁴, R⁴ and R⁵ or R⁵ and R⁸ form together a condensedC₄-C₇ ring that optionally can be substituted with one or more R groups;

[0020] the group R⁶ is selected from the group consisting of a linear orbranched, saturated or unsaturated C₁-C₂₀ allyl, C₆-C₂₀ aryl and C₇-C₂₀arylalkyl radical, optionally containing heteroatoms belonging to groups13 or 15-17 of the Periodic Table of the Elements;

[0021] the substituents L, equal to or different from each other, aremonoanionic sigma ligands selected from the group consisting ofhydrogen, halogen, -R, -OR, -OCOR, -OSO₂CF₃, -SR, -NR₂ and -PR₂, whereinR has the meaning reported above;

[0022] Y² is selected from the group consisting of CR⁸ or Y¹; and

[0023] m is 0 or 1; when the group Y² is a CR⁸ group m is l and the 6membered ring formed is an aromatic benzene ring, when Y² is differentfrom CR⁸ m is 0 and the carbon atom bonding the R⁴ group is directlybonded to the cyclopentadienyl ring and the ring formed is a 5 memberedring; i.e. when m is 1 the compound of formula (I) has the followingformula (Ia);

[0024] and when m is 0 the compound of formula (I) has the followingformula (Ib);

[0025] wherein L, X, Z, Y¹, m, R¹, R², R³, R⁴, R⁵, R⁶ and R⁸ have themeaning reported above; and

[0026] (B) an activating cocatalyst.

[0027] The present invention further concerns a titanium complex offormula (I), as reported above, as well as the corresponding ligand offormula (II):

[0028] wherein X, Z, Y¹, m, R¹, R² , R³, R⁴, R⁵, R⁶ and R⁸ have themeaning reported above; the above ligands are particularly useful asintermediates in the preparation of the titanium complexes of formula(I), according to the invention.

[0029] The titanium complex of formula (I) may be suitably usedaccording to the present invention in a complexed form, for example inthe presence of a coordination molecules such as Lewis bases. Preferredcomplexes of formula (I) are those belonging to the following threeclasses (1), (2) and (3), having respectively formula (III), (IV) and(V).

[0030] Class (1)

[0031] Titanium complexes belonging to class (1) have the followingformula (III)

[0032] wherein X, Z, Y¹, L, R¹, R², R³, R⁴, R⁵, R⁶ and R⁸ have themeaning reported above with the proviso that R² and R³ do not form acondensed aromatic or aliphatic C₄-C₇ ring.

[0033] Preferably in the titanium complexes of formula (III):

[0034] X is a nitrogen atom; the divalent bridge >ZR¹ ₂ is preferablyselected from the group consisting of dimethylsilyl, diphenylsilyl,diethylsilyl, di-n-propylsilyl, di-isopropylsilyl, di-n-butyl-silyl,di-t-butyl-silyl, di-n-hexylsilyl, ethylmethylsilyl, n-hexylmethylsilyl,cyclopentamethylenesilyl, cyclotetramethylenesilyl,cyclotrimethylenesilyl, methylene, dimethylmethylene anddiethylmethylene; even more preferably, it is dimethylsilyl,diphenylsilyl or dimethylmethylene;

[0035] Y¹ is N-methyl, N-ethyl or N-phenyl;

[0036] R² and R³ ,equal to or different from each other, are selectedfrom the group consisting of hydrogen, halogen, -R, -OR, -OCOR,-OSO₂CF₃, -SR, -NR₂ and -PR₂; more preferably R² is hydrogen methyl,ethyl, propyl or phenyl; and R³ is hydrogen methyl or phenyl; even morepreferably R² is hydrogen or methyl;

[0037] R⁴ and R⁸ are hydrogen;

[0038] R⁵ is hydrogen, methoxy or tertbutyl;

[0039] R⁶ is selected from the group consisting of methyl, ethyl,n-propyl, isopropyl, n-butyl, t-butyl, phenyl, p-n-butyl-phenyl, benzyl,cyclohexyl and cyclododecyl; more preferably R⁶ is t-butyl; thesubstituents L, equal to or different from each other, are preferablyhalogen atoms, linear or branched, saturated or unsaturated C₇-C₂₀alkylaryl, C₁-C₆ alkyl groups or OR wherein R is described above; morepreferably the substituents L are Cl, CH₂C₆H₅, OCH₃ or CH₃.

[0040] Non limiting examples of complexes of formula (III) are:

[0041] and the corresponding titanium dichloride or dimethoxy complexes.

[0042] The titanium complexes belonging to class (1) can be preparedstarting from the ligand of formula (IIIa)

[0043] wherein X, Z, Y¹, R¹, R², R³, R⁴, R⁵, R⁶ and R⁸ have the meaningreported above.

[0044] Class (2)

[0045] Titanium complexes of class (2) have the following formula (IV)

[0046] wherein X, Z, Y¹, L, R¹, R⁴, R⁵, R⁶, R⁸, and R⁹ have the meaningreported above and k ranges from 0 to 4.

[0047] Preferably in the titanium complexes of formula (IV):

[0048] X is a nitrogen atom; the divalent bridge >ZR¹ ₂ is selected fromthe group consisting of dimethylsilyl, diphenylsilyl, diethylsilyl,di-n-propylsilyl, di-isopropylsilyl, di-n-butyl-silyl, di-t-butyl-silyl,di-n-hexylsilyl, ethylmethylsilyl, n-hexylmethylsilyl,cyclopentamethylenesilyl, cyclotetramethylenesilyl,cyclotrimethylenesilyl, methylene, dimethylmethylene anddiethylmethylene; even more preferably, it is dimethylsilyl,diphenylsilyl or dimethylmethylene;

[0049] Y¹ is N-methyl, N-ethyl or N-phenyl;

[0050] k is 0 or 1 and R⁹ is 2-methyl, 2-isopropyl and 2-tert-butyl;

[0051] R⁶ is selected from the group consisting of methyl, ethyl,n-propyl, isopropyl, n-butyl, t-butyl, phenyl, p-n-butyl-phenyl, benzyl,cyclohexyl and cyclododecyl; more preferably R⁶ is t-butyl;

[0052] R⁴, R⁵ and R⁸ are hydrogen atoms;

[0053] the substituents L, equal to or different from each other, arehalogen atoms, linear or branched, saturated or unsaturated C₁-C₆ alkyl,C₇C₂₀ allylaryl groups or OR wherein R is defined above;

[0054] more preferably the substituents L are Cl, CH₃, OCH₃ or CH₂C₆H₅.

[0055] Non limiting examples of titanium complexes of formula (IV),according to the present invention, are the following:

[0056] and the corresponding titanium dimethyl or dimethoxy complexes.

[0057] The titanium complexes belonging to class (2) can be preparedstarting from the ligand of formula (IVa)

[0058] wherein X, Z, Y¹, R¹, R⁴, R⁵, R⁶, R⁸, R⁹ and k have the meaningreported above.

[0059] Class (3)

[0060] Titanium complexes belonging to class (3) have the followingformula (V):

[0061] wherein X, Z, L, Y¹, R¹, R², R³, R⁴, R⁵ and R⁶ have the meaningreported above.

[0062] Preferably in the titanium complexes of formula (IV):

[0063] X is a nitrogen atom; the divalent bridge >ZR¹ ₂ is preferablyselected from the group consisting of dimethylsilyl, diphenylsilyl,diethylsilyl, di-n-propylsilyl, di-isopropylsilyl, di-n-butyl-silyl,di-t-butyl-silyl, di-n-hexylsilyl, ethylmethylsilyl, n-hexylmethylsilyl,cyclopentamethylenesilyl, cyclotetramethylenesilyl,cyclotrimethylenesilyl, methylene, dimethylmethylene anddiethylmethylene; even more preferably, it is dimethylsilyl,diphenylsilyl or dimethylmethylene;

[0064] two Y¹ are the same group; more preferably they are NR⁷ or S;

[0065] R² is hydrogen, methyl, ethyl, propyl or phenyl; and R³ ishydrogen or R² and R³ form a condensed benzene ring that can besubstituted with one or more R groups;

[0066] R⁴ is hydrogen and R⁵ is hydrogen methyl, ethyl, propyl or phenylor R⁴ and R⁵ form a condensed benzene ring that can be substituted withone or more R groups;

[0067] R⁶ is preferably selected from the group consisting of methyl,ethyl, n-propyl, isopropyl, n-butyl, t-butyl, phenyl, p-n-butyl-phenyl,benzyl, cyclohexyl and cyclododecyl; more preferably R⁶ is t-butyl;

[0068] the substituents L, equal to or different from each other, arepreferably halogen atoms linear or branched, saturated or unsaturatedC₇-C₂₀ alkylaryl, C₁-C₆ alkyl groups or OR; more preferably thesubstituents L are Cl, CH₂C₆H₅, OCH₃ or CH₃.

[0069] Non limiting examples of complex of formula (IV) are:

[0070] and the corresponding titanium dichloride or dimethoxy complexes.

[0071] The titanium complexes belonging to class (3) can be preparedstarting from the ligand of formula (Va)

[0072] wherein X, Z, Y¹, R¹, R², R³, R⁴, R⁵ and R⁶ have the meaningreported above.

[0073] The ligands of formula (II) can be prepared by a processcomprising the following steps:

[0074] i) reacting a compound of formula (VI):

[0075] wherein Y¹, m, Y², R², R³, R⁴, R⁵, and R⁸ have the meaningreported above, with at least one equivalent of a base such ashydroxides and hydrides of alkali metals or alkaline-earth metals,metallic sodium and potassium or organolithium compounds such asbuthilithium, methilithium, and then contacting the obtained compoundwith a compound of formula R¹ ₂ZY³Y⁴, wherein R¹ and Z have the meaningreported above, Y³ is a halogen atom preferably chlorine and Y⁴ is anhalogen atom preferably chlorine or a group R⁶XH wherein R⁶ and X havethe meaning reported above and H is hydrogen;

[0076] ii) if Y⁴ is an halogen atom, reacting the obtained product witha compound of formula R⁶XH₂ wherein R⁶ and X have the meaning reportedabove and H is hydrogen and recovering the product.

[0077] Compound of formula VI can be prepared according to generalprocedures known in the state of the art, starting from commerciallyobtainable products or from derivatives which can be prepared by knownmethods. Synthesis of compounds of formula (VI) can be found for examplein WO 99124446, EP 99204566, EP 99204565 and PCT/EP00/13191.

[0078] The ligand can be finally purified by general procedures known inthe state of the art, such as crystallization or chromatography. All thesteps are carried out in an aprotic solvent that can be a polar orapolar solvent. Not limitative examples of aprotic polar solvents whichcan be used in the above process are tetrahydrofurane, dimethoxyethane,diethylether and dichloromethane. Not limitative examples of apolarsolvents suitable for the above process are toluene, pentane, hexane andbenzene. The temperature in the various steps is preferably kept between−180° C. and 80° C., and more preferably between −20° C. and 40° C.

[0079] The titanium complexes of formula (I) can be prepared by firstreacting a ligand of formula (II), prepared as described above, with acompound able to form a delocalized dianion, such as hydroxides andhydrides of alkali metals or alkaline-earth metals, metallic sodium andpotassium or organolithium compounds such as butylithium, methylithium,on the cyclopentadienyl ring and on the group X, and thereafter with acompound of formula TiL′₄, wherein the substituents

[0080] L′ are halogen or -OR, wherein R has the meaning reported above.Non limiting examples of compounds of formula TiL′₄ are titaniumtetrachloride and titanium tetramethoxy.

[0081] According to a preferred method, a ligand (II) is dissolved in anaprotic polar solvent and at least two equivalents of an organic lithiumcompound are added. The thus obtained anionic compound is added to asolution of the compound TiL′₄ in an aprotic solvent. At the end of thereaction, the solid product obtained is separated from the reactionmixture by techniques commonly used in the state of the art. Nonlimiting examples of aprotic polar solvents suitable for the abovereported processes are tetrahydrofurane, dimethoxyethane, diethyletherand dichloromethane. Not limiting examples of apolar solvents suitablefor the above process are pentane, hexane and toluene. During the wholeprocess, the temperature is preferably kept between −180° C. and 80° C.,and more preferably between −20° C. and 40° C.

[0082] All the above processes are carried out in inert atmosphere suchas nitrogen.

[0083] Titanium compounds of formula (I) in which at least one Lsubstituent is different from halogen can be conveniently prepared bymethods known in the state of the art for example, such compounds may beobtained by reacting the dihalogenated metallocene with alkylmagnesiumhalides (Grignard reagents) or with lithiumalkyl compounds.

[0084] When one or both L substituents are alkyl, the above titaniumcomplexes (I) can be conveniently obtained by reacting directly a ligandof formula (II) with at least one molar equivalent of a compound offormula TiCl₄, in the presence of at least 3 molar equivalents of asuitable alkylating agent; said alkylating agent can be an alkaline oralkaline-earth metal, such as dialkyl-lithium, dialkyl-magnesium or aGrignard reagent, as described in WO 99/36427 and WO 00/75151.

[0085] An alternative process for preparing titanium complex of formula(I) in which both L substituents are OR groups comprises to prepare thetitanium complex of formula (I) in which two L groups are R and thencontact the obtained complex with oxygen. The resulting derivativehaving as L substituents two OR groups shows a better stability than thecorrespondent R substituted complex and therefore they can be stored fora long time without losing activity.

[0086] Suitable activating cocatalyst according to the process of theinvention are alumoxanes or compounds able to form an alkyl metallocenecation.

[0087] Alumoxane useful as cocatalyst (B) may be linear alumoxanes ofthe formula (VII):

[0088] wherein R¹⁰ is selected from the group consisting of halogen,linear or branched, saturated or unsaturated C₁-C₂₀ alkyl, C₃-C₂₀cycloalkyl, C₆-C₂₀ aryl, C₇-C₂₀ alkylaryl and C₇-C₂₀ arylalkyl radicalsand y ranges from 0 to 40;

[0089] or cyclic alumoxanes of the formula (VIII):

[0090] wherein R¹⁰ has the meaning described above and y is an integerranging from 2 to 40.

[0091] The above alumoxanes may be obtained according to proceduresknown in the state of the art, by reacting water with an organo-aluminumcompound of formula AIR¹⁰ ₃ or Al₂R¹⁰ ₆, with the condition that atleast one R¹⁰ is not halogen. In this case, the molar ratios of Al/waterin the reaction is comprised between 1:1 and 100:1. Particularlysuitable are the organometallic aluminum compounds of formula (II)described in EP 0 575 875 and those of formula (II) described in WO96/02580. Moreover, suitable cocatalysts are those described in WO99/21899 and in PCT/EP00/091111.

[0092] The molar ratio between aluminum and the metal of the titaniumcomplex is comprised between about 10:1 and about 5000:1, and preferablybetween about 100:1 and about 4000:1.

[0093] Examples of alumoxanes suitable as activating cocatalysts in theprocess of the invention are methylalumoxane (MAO),tetra-isobutyl-alumoxane (TIBAO), tetra-2,4,4-trimethylpentyl-alumoxane(TIOAO) and tetra-2-methyl-pentylalumoxane. Mixtures of differentalumoxanes can also be used.

[0094] Not limiting examples of aluminum compounds of formula AlR¹⁰ ₃ orAl₂R¹⁰ ₆ are:

[0095] tris(methyl)aluminum, tris(isobutyl)aluminum,

[0096] tris(isooctyl)aluminum, bis(isobutyl)aluminum hydride,

[0097] methyl-bis(isobutyl)aluminum, dimethyl(isobutyl)aluminum,

[0098] tris(isohexyl)aluminum, tris(benzyl)aluminum,

[0099] tris(tolyl)aluminum, tris(2,4,4-trimethylpentyl)aluminum,

[0100] bis(2,4,4-trimethylpentyl)aluminum hydride,isobutyl-bis(2-phenyl-propyl)aluminum,

[0101] diisobutyl-(2-phenyl-propyl)aluminum,isobutyl-bis(2,4,4-trimethyl-pentyl)aluminum,

[0102] diisobutyl-(2,4,4-trimethyl-pentyl)aluminum,tris(2,3-dimethyl-hexyl)aluminum,

[0103] tris(2,3,3-trimethyl-butyl)aluminum,tris(2,3dimethyl-butyl)aluminum,

[0104] tris(2,3-dimethyl-pentyl)aluminum,tris(2-methyl-3-ethyl-pentyl)aluminum,

[0105] tris(2-ethyl-3-methyl-butyl)aluminum,tris(2-ethyl-3-methyl-pentyl)aluminum,

[0106] tris(2-isopropyl-3-methyl-butyl)aluminum andtris(2,4-dimethyl-heptyl)aluminum.

[0107] Particularly preferred aluminum compounds are trimethylaluminum(TMA), tris(2,4,4-trimethylpentyl) aluminum (TIOA), triisobutylaluminum(TIBA), tris(2,3,3-trimethyl-butyl)aluminum andtris(2,3-dimethyl-butyl)aluminum.

[0108] Mixtures of different organometallic aluminum compounds and/oralumoxanes can also be used. In the catalyst system used in the processof the invention, both said titanium complex and said alumoxane can bepre-reacted with an organometallic aluminum compound of formula AlR¹⁰ ₃or Al₂R¹⁰ ₆, wherein R¹⁰ has the meaning reported above. Pre reactiontime can vary from 20 seconds to 1 hour, preferably from 1 minute to 20minutes.

[0109] Further activating cocatalysts suitable as component (B) in thecatalysts of the invention are those compounds capable of forming analkylmetallocene cation; preferably, said compounds have formula Q⁺W⁻,wherein Q⁺ is a Bronsted acid capable of donating a proton and ofreacting irreversibly with a substituent L of the compound of formula(I), and W⁻ is a compatible non-coordinating anion, capable ofstabilizing the active catalytic species which result from the reactionof the two compounds, and which is sufficiently labile to bedisplaceable by an olefinic substrate. Preferably, the W⁻ anioncomprises one or more boron atoms. More preferably, the anion W⁻ is ananion of formula BAr₄ ⁽⁻⁾, wherein the Ar substituents, equal to ordifferent from each other, are aryl radicals such as phenyl,pentafluorophenyl, bis(trifluoromethyl)phenyl.Tetrakis-pentafluorophenyl-borate is particularly preferred. Moreover,compounds of formula BAr₃ can be conveniently used.

[0110] The catalysts system of the present invention can also besupported on an inert carrier (support), by depositing the titaniumcomplex (A), or the reaction product of the titanium complex (A) withthe cocatalyst (B), or the cocatalyst (B) and successively the titaniumcomplex (A), on the inert support, such as silica, alumina, magnesiumhalides, olefin polymers or prepolymers (i.e. polyethylenes,polypropylenes or styrene-divinylbenzene copolymers). The thus obtainedsupported catalyst system, optionally in the presence of alkylaluminumcompounds, either untreated or pre-reacted with water, can be usefullyemployed in gas-phase polymerization processes. The solid compound soobtained, in combination with further addition of the alkyl aluminumcompound as such or prereacted with water, is usefully employed in gasphase polymerization.

[0111] The polymerization yield depends on the purity of metallocenes inthe catalyst; the metallocene according to the present invention may beused as such or may be previously subjected to purification treatments.

[0112] Catalyst components (A) and (B) may be suitably contacted amongthem before the polymerization. The contact time may be comprisedbetween 1 and 60 minutes, preferably between 5 and 20 minutes. Thepre-contact concentrations for the titanium complex (A) are comprisedbetween 0.1 and 10⁻⁸ mol/l, whereas for the cocatalyst (B) they arecomprised between 2 and 10⁻⁸ mol/l. The precontact is generally carriedout in the presence of a hydrocarbon solvent and, optionally, of smallamounts of monomer.

[0113] The catalysts of the present invention are particularlyadvantageous in propylene polymerization, wherein they givesubstantially amorphous propylene polymers with high activities. When inthe compounds of formula (I) Y¹ is NR⁷ and preferably the compounds offormula (I) belong to classes (1) and (2), the propylene polymersobtained with the process of the invention have predominantlysyndiotactic structure. The syndiotacticity of a polyolefins can beconveniently defined by the percent content of rr triads, as describedin L. Resconi et al, Chemical Reviews, 2000, 100, 1253. When in thecompounds of formula (I) Y¹ is NR⁷ and preferably the compounds offormula (I) belong to classes (1) and (2), the propylene polymersobtained with the process of the present invention typically have triadcontents in the range 60-80%, more preferably 65-75%. Theirsyndiotacticity is not high enough to produce substantial crystallinity(as measured by DSC), but it is high enough to generate resiliency inthe polypropylene.

[0114] Being substantially void of crystallinity, their melting enthalpy(ΔH_(f)) is preferably lower than about 20 J/g and even more preferablylower than about 10 J/g.

[0115] A further interesting use of the catalysts according to thepresent invention is directed to the preparation of propylene-basedcopolymers, wherein suitable comonomers are ethylene, alpha-olefins offormula CH₂═CHR′ wherein R′ is a linear or branched, C₂-C₁₀ alkyl suchas for example 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, nonconjugate diolefins containing up to 20 carbon atoms, for examples saiddiolefins can belong to the formula CH₂═CH-(CR″₂)_(h)-CR″₂═CR″ whereinR″ is hydrogen or a linear or branched, C₁-C₁₀ alkyl and h ranges from 1to 15, such as 1,4hexadiene, 1,5-hexadiene, 2-methyl-1,5-hexadiene,7-methyl-1,6-octadiene, 1,7-octadiene, and the like or said olefins canbe norbornene or its derivatives such as 5-ethylidene-2-norbornene.

[0116] The preferred ranges of composition depend on the type of polymerdesired, and on the type of polymerization process employed. Forexample, in the case of amorphous copolymers of propylene with ethylene,such as those described in EP 729984, the content of ethylene rangesfrom 1 to 35% by moles preferably from 5 to 20% by moles. In the case ofethylene/propylene elastomers the content of propylene ranges from 20 to80 wt %, preferably from 70to 30 wt %, while in ethylene/propylene/dieneelastomers the content of the diene, which preferably isethylidenenorbornene or 1,4-hexadiene, range from 0.5 to 5 wt %.

[0117] Moreover, the molecular weight of the polymers can be varied bychanging the polymerization temperature or the type or the concentrationof the catalyst components, or by using molecular weight regulators,such as hydrogen, as well-known in the state of the art. The molecularweight of the propylene-based polymers may be also easily controlled bycopolymerizing small amounts of ethylene.

[0118] The polymerization process according to the present invention canbe carried out in gaseous phase or in liquid phase, optionally in thepresence of an inert hydrocarbon solvent either aromatic (such astoluene), or aliphatic (such as propane, hexane, heptane, isobutane andcyclohexane).

[0119] The polymerization temperature ranges from about 0° C. to about180° C., preferably from 40° C. to 120° C., more preferably from 60° C.to 90° C.

[0120] The molecular weight distribution can be varied by using mixturesof different metallocenes or by carrying out the polymerization invarious steps differing in the polymerization temperature and/or in theconcentration of the polymerization monomers.

[0121] The following examples are reported for illustrative and notlimiting purposes.

[0122] GENERAL PROCEDURES AND CHARACTERIZATIONS

[0123] All operations were performed under nitrogen by usingconventional Schlenk-line techniques. Solvents were purified bydegassing with N₂ and passing over activated (8 hours, N₂ purge, 300°C.) Al₂O₃, and stored under nitrogen. The cocatalyst was a commercialMAO from Witco AG (10% wt solution in toluene).Me₂Si(Me₄Cp)(NtBu)TiCl₂was purchased from Witco AG.

[0124]¹H-NMR

[0125] The proton spectra of ligands and metallocenes were obtainedusing a Bruker DPX 200 spectrometer operating in the Fourier transformmode at room temperature at 200.13 MHz. The samples were dissolved inCDCl₃, CD₂Cl₂, C₆D₆ or C₆D₅CD₃. As a reference, the residual peak ofCHCl₃, CHDCl₂, C₆D₅H or C₆D₅CH₃ in the ¹H spectra (7.25 ppm, 5.35 ppm,7.15 and 2.10 ppm respectively) were used. Proton spectra were acquiredwith a 15° pulse and 2 seconds of delay between pulses; 32 transientswere stored for each spectrum. All NMR solvents were dried overactivated molecular sieves, and kept under nitrogen. Preparation of thesamples was carried out under nitrogen using standard inert atmospheretechniques.

[0126]¹³C-NMR

[0127] Carbon spectra were obtained using a Bruker DPX-400 spectrometeroperating in the Fourier transform mode at 120° C. at 100.61 MHz. Thesamples were dissolved in C₂D₂Cl₄. The peak of the mmmm pentad in the¹³C spectra (21.8 ppm) was used as a reference. The carbon spectra wereacquired with a 90° pulse and 12 seconds of delay between pulses. About3000 transients were stored for each spectrum. The ethylene content wasdetermined according to M. Kakugo, Y. Naito, K. Mizunuma, T. Miyatake,Macromolecules 1982, 15, 1150. The 1-butene content was determined fromthe diad distribution, from the S_(αα) carbons, as described in J. C.Randall, Macromolecules 1978, 11, 592.

[0128] GC-MS

[0129] GC-MS analyses were carried out on a HP 5890—series 2 gaschromatograph and a BP 5989B quadrupole mass spectrometer.

[0130] VISCOSITY MEASUREMENTS

[0131] The intrinsic viscosity (I.V.) was measured intetrahydronaphtalene (T) at 135° C.

[0132] The polymer molecular weights were determined from the viscosityvalues.

[0133] DSC ANALYSIS

[0134] Melting point and heat of fusion measurements were carried out ona Perkin Elmer DSC 7 instrument by heating the sample from 25° C. to200° C. at 10° C./min, holding for 2 min at 200° C., cooling from 200°C. to 25° C. at 10° C./min, holding for 2 min at 25° C., heating from25° C. to 200° C. at 10° C./min. The reported values are thosedetermined from the second heating scan. T_(g) values were determined ona DSC30 Mettler instrument equipped with a cooling device, by heatingthe sample from 25° C. to 200° C. at 20° C./min, holding for 10 min at200° C., cooling from 200° C. to −140° C., holding for 2 min at −140°C., heating from −140° C. to 200° C. at 20° C./min. The reported valuesare those determined from the second heating scan.

EXAMPLE 1

[0135] synthesis ofdimethylsilyl(tert-butylamido)(N-methyl-2-methyl-5,6-dihydroindeno[2,1-b]indol-6-yl)dimethyltitanium (B-1)

[0136] First Synthetic route

[0137] (a) Synthesis of 2-methyl-5,6-dihydroindeno[2,1-b]indole

[0138] All operations were carried out in air, with out-of-the bottlesolvents and reagents: isopropanol, RPE Carlo Erba (99%); 2-indanone,Chemische Fabrik Berg (98%); p-tolyl-hydrazine hydrochloride, Aldrich(98%).

[0139] In a 1-L jacketed glass reactor (Büchi) with magnetically driven,three blade stirrer, connected to a thermostat for temperature control,were charged 85.0 g of 2-indanone (Mw=132.16, 0.63 mol), 102.0 g ofp-MeC₆H₄NHNH₂·HCl (Mw=158.63, 0.63 mol) and 0.5 L of i-PrOH. The thicksuspension was warmed to 80° C. in about 30 minutes and the slurrydarkened to dark brown under stirring. The mixture was stirred at 80° C.for 1 hour and then was cooled to room temperature in about 30 minutes.

[0140] The slurry was siphoned into 1.2 L of water containing 1.5equivalents of NaHCO₃, thus obtaining a fine dispersion of a dark greenproduct (no heat evolution was observed). The slurry was then filteredon a G3 frit, washed with water, dried in air under moderate vacuum,then in the rotating evaporator at 80° C. and finally under high vacuum(mechanical pump). 121.2 g of the target product were obtained with ayield of 87.3% (purity of 99.6% by G.C.)

[0141]¹H-NMR (CDCl₃, δ, ppm): 2.52 (s, 3H, CH₃); 3.70 (s, 2H, CH₂);7.01-7.66 (m, 7H, Ar); 8.13 (bs, 1H, N—H).

[0142] (b) Synthesis of N-methyl-2-methyl-5,6-dihydroindeno[2,1-b]indole

[0143] 10.2 g of 2-methyl-5,6-dihydroindeno[2,1-b]indole (Mw=219.28,purity 99.6%, 46.33 mmol), obtained as reported above, were dissolved in100 mL of 1,3-dioxolane (Aldrich) at room temperature. 5.42 g oftert-BuOK (Fluka, 97%, Mw=112.22, 46.85 mmol) were then added; thesolution changed color from green to dark brown and was stirred at roomtemperature for 10 minutes; then 2.90 mL of MeI (Mw=141.94, d=2.280,46.58 mmol) were added. After 15 minutes of stirring, a solid startedforming. Stirring was continued for 1 hour, then the reaction mixturewas poured into water containing 4 g of NH₄Cl. The formed solid wasisolated by filtration and dried in vacuo, to obtain 9.5 g of the targetproduct as a microcrystalline brown solid in pure state, with a yield of86.3% (purity of 98.2% by G.C.).

[0144]¹H-NMR (CDCl₃, δ, ppm): 2.52 (s, 3H, CH₃); 3.68 (s, 2H, CH₂); 3.78(s, 3H, N—CH₃); 7.02-7.64 (m, 7H, Ar).

[0145] (c) Synthesis ofchlorodimethyl(N-methyl-2-methyl-5,6-dihydroindeno[2,1-b]indol-6-yl)silane

[0146] 9.5 mL of a 2.5 M solution of n-BuLi in hexane (23.75 mmol) wereadded dropwise to a solution of 5.1 g ofN-methyl-2-methyl-5,6-dihydroindeno[2,1-b]indole, obtained as reportedabove, (purity 98.2%, Mw=233.32, 21.46 mmol; indenoindole: n-BuLi=1:1.1)in 70 mL of THF, previously cooled to −78° C. At the end of theaddition, the brown solution was allowed to warm up to room temperatureand stirred for 6 hours. Then it was cooled again to −78° C. and addeddropwise to a solution of dichlorodimethylsilane (Mw=129.06, d=1.064,2.6 mL, 21.43 mmol; indenoindole: Me₂SiCl₂=1:1) in 20 mL of THF,previously cooled to −78° C. At the end of the addition, the reactionmixture was allowed to warm up to room temperature and stirredovernight. The solvents were evaporated under reduced pressure to give abrown sticky solid, which at the ¹H-NMR analysis resulted to be thetarget product, with few by-products.

[0147] The product was used in the subsequent step without furtherpurification.

[0148]¹H-NMR (CDCl₃, δ, ppm): −0.13 (s, 3H, Si—CH₃); 0.48 (s, 3H,Si—CH₃); 2.53 (s, 3H, CH₃); 3.44 (s, 1H, CH); 3.88 (s, 3H, N—CH₃);6.90-7.71 (m, 7H, Ar).

[0149] (d) Synthesis of6-[dimethylsilyl(tert-butylamino)]N-methyl-2-methyl-5,6-dihydroindeno[2,1-b]indole

[0150] 3.96 g ofchlorodimethyl(N-methyl-2-methyl-5,6-dihydroindeno[2,1-b]indol-6-yl)silane(Mw=325.92, 12.15 mmol), obtained as described above, were dissolved in50 mL of toluene and added at −78° C. to a solution of t-BuNH₂ (3.0 mL,Mw=73.14, d=0.696, 28.55 mmol) in 20 mL of toluene. At the end of theaddition, the reaction mixture was allowed to warm up to roomtemperature and stirred for 2 days to give a black suspension, which wasfiltered to remove the ammonium salt formed. The filtrate wasconcentrated under vacuum, obtaining 3.49 g of the target product, as ablack sticky solid (raw yield=79.2%).

[0151]¹H-NMR (CDCl₃, δ, ppm): −0.15 (s, 3H, Si—CH₃); −0.04 (s, 3H,Si—CH₃); 1.23 (s, 9H, t-Bu); 2.52 (s, 3H, CH₃); 3.44 (s, 1H, CH); 3.86(s, 3H, N—CH₃); 6.90-7.71 (m, 7H, Ar).

[0152] (e) Synthesis ofdimethylsilyl(tert-butylamido)(N-methyl-2-methyl-5,6-dihydroindeno[2,1-b]indol-6-yl)dimethyltitanium

[0153] 25.3 mL of a 1.6 M solution of MeLi in diethylether (40.48 mmol)were added dropwise at room temperature to a solution of 3.49 g of6-[dimethylsilyl(tert-butylamino)]N-methyl-2-methyl-5,6-dihydroindeno[2,1-b]indole(Mw=362.60, 9.62 mmol), obtained as reported above, in 45 mL of Et₂O.The reaction mixture was stirred overnight: an increasing turbiditydeveloped with final formation of a black suspension. Then 1.05 mL ofTiCl₄ (Mw 189.71, d=1.730, 9.62 mmol) in 40 mL of pentane were slowlyadded at room temperature, and the resulting mixture was stirredovernight. The solvents were removed under reduced pressure to give ablack sticky solid, which was extracted with 50 mL of toluene. Theextract was then concentrated, yielding 3.02 g of the desired compoundas a black powder (raw yield=71.6%).

[0154]¹H-NMR (C₆D₆, δ, ppm): −0.02 (s, 3H, Ti—CH₃); 0.07 (s, 3H,Ti—CH₃); 0.56 (s, 3H, Si—CH₃); 0.74 (s, 3H, Si—CH₃); 1.41 (s, 9H, t-Bu);2.45 (s, 3H, CH₃); 3.12 (s, 3H, N—CH₃); 6.90-7.94 (m, 7H, Ar).

[0155] Second Synthetic route

[0156] (a) Synthesis of N-methyl-2-methyl-5,6-dihydroindeno[2,1-b]indole

[0157] 22.37 g of 2-methyl-5,6-dihydroindeno[2,1-b]indole (99.6% byG.C., Mw=219.28, 101.6 mmol) were dissolved into 220 mL of 1,3-dioxolane(Aldrich) at room temperature and added of 11.46 g of t-BuOK (Aldrich,Mw=112.22, 101.6 mmol). The solution changed color from green to darkbrown and was stirred at room temperature for 10 minutes; then 6.33 mLof MeI (Acros, Mw=141.94, d=2.280, 101.6 mmol) were added. After 15minutes stirring, a solid started forming. Stirring was continued for 1hour, then the reaction mire was poured into water containing 8 g ofNH₄Cl (Carlo Erba RPE, purity 99.5%). After two hours stirring, theformed solid was isolated by filtration and dried in vacuo to give 23.2g of a brown powder, which was analyzed by NMR spectroscopy and GC-MS.The GC-MS analysis showed a purity in the desired product of 91.5%(yield=89.5%). 2-methyl-5,6-dihydroindeno[2,1-b]indole andN-methyl-2,6-dimethyl-5,6-hydroindeno[2,1-b] indole were also present,in percentage of 2.6% and 3.7%, respectively.

[0158] An aliquot of the product (9.98 g) was suspended in 150 mL ofMeOH (Carlo Erba RPE, purity 99.9%, b.p.=64.6° C.). After 30 minstirring at room temperature, a dark brown microcrystalline powder wasisolated by filtration (9.18 g). The GC-MS analysis showed a higherpurity (99.0%) in the desired product.

[0159]¹H NMR (CDCl₃, δ, ppm): 2.53 (s, 3H, CH₃); 3.65 (s, 2H, CH₂); 3.76(s, 3H, N—CH₃); 7.00-7.60 (m, 7H, Ar).

[0160]¹³C NMR (CDCl₃, δ, ppm): 21.52 (CH₃); 29.98 (CH₂); 31.08 (N—CH3);109.38; 118.11; 119.13; 121.83; 122.14; 122.26; 124.62; 126.95; 129.11(2C); 139.59; 140.50; 142.14; 148.87.

[0161] m/z (%): 233 (100) [M⁺]; 218 (35).

[0162] (b) Synthesis of (tert-butylamino)dimethylchlorosilane

[0163] 15.7 mL of Me₂SiCl₂ (Mw=129.06, d=1.07, 130.21 mmol) in 20 mL ofEt₂O were added dropwise at 0° C. to a solution of 20.0 g of t-BuNH₂(Mw=73.14, d=0.696, 273.44 mmol, t-BuNH₂: Me₂SiCl₂=2.1:1) in 40 mL ofEt₂O. The resulting solution was allowed to warm up to room temperatureand stirred for 1.5 hours. It was observed a colors change from yellowto light yellow with final formation of a white milky suspension. Thelatter was filtered and the filtrate concentrated in vacuo to give 18.93g of a light yellow oil, which by ¹H-NMR analysis appeared to be mainlythe target product, together with a by-product, identified asdi(t-butylamino)dimethylsilane. The silylamine was used in thesubsequent step without further purification. Yield 65.8% (purity by ¹HNMR=75.0% mol.)

[0164]¹H-NMR (CD₂Cl₂, δ, ppm): 0.48 (s, 6H, Si—CH₃); 1.26 (s, 9H, t-Bu);1.42 (bs, 1H, NH).

[0165] (c) Synthesis of6[dimethylsilyl(tert-butylamino)]N-methyl-2-methyl-5,6-dihydroindeno[2,1-b]indole

[0166] 6.66 mL of n-BuLi 2.5 M in hexane (16.65 mmol) were addeddropwise at 0° C. to a solution of 3.53 g ofN-methyl-2-methyl-5,6-dihydroindeno[2,1-b]indole (Mw=233.32, purity99.0%, 15.13 mmol) in Et₂O. At the end of the addition, the reactionmixture was allowed to warm up to room temperature and stirred for twohours. Subsequently, 3.34 g of (tert-butylamino)dimethylchlorosilane(Mw=165.74, purity 75.0% mol., d=0.887, 20.17 mmol) were added at 0° C.to the Li salt suspension and the resulting mixture was allowed to warmup to room temperature. After three hours stirring, the solvents wereevaporated under reduced pressure and the residue was dissolved in 50 mLof toluene, obtaining a dark brown suspension, which was filtered. Thefiltrate was evaporated to dryness under reduced pressure, obtaining5.86 g of a dark brown oil, which resulted to be 86.5% wt. pure(calculated by ¹H-NMR). Yield=92.4%.

[0167]¹H-NMR (C₆D₆, δ, ppm): −0.14 (s, 3H, Si—CH₃); −0.13 (s, 3H,Si—CH₃); 0.99 (s, 9H, t-Bu); 2.54 (s, 3H, CH₃); 3.27 (s, 3H, N—CH₃);3.40 (s, 3H, CH); 7.10-7.90 (m, 7R, Ar). m/z (%): 362 (39) [M⁺]; 232(16); 130 (100); 74 (18).

[0168] (d) Synthesis ofdimethylsilyl(tert-butylamido)(N-methyl-2-methyl-5,6-dihydroindeno[2,1-b]indol-6yl)dimethyltitanium

[0169] 19.14 mL of a 1.6 M solution of MeLi in diethylether (30.63 mmol)were added dropwise at 0° C. to a solution of 2.76 g of6-[dimethylsilyl(tert-butylamino)]N-methyl-2-methyl-5,6-dihydroindeno[2,1-b]indole(Mw=362.60, 7.62 mmol), obtained as reported above, in 40 mL of Et₂O.The resulting dark brown solution was allowed to warm up to roomtemperature and stirred for 1.5 hours. Then 0.84 mL of TiCl₄ (Mw=189.71,d=1.730, 7.63 mmol) in 4 mL of pentane were slowly added at roomtemperature and the resulting black suspension stirred for 1.5 hours.The solvents were removed under reduced pressure and the residue wasextracted with 50 mL of toluene. The extract (3.07 g) was added of 70 mLof pentane, the resulting dark brown suspension stirred for 30 min atroom temperature and filtered, giving as residue a light brown powder,which was dried and analyzed by ¹H-NMR. The ¹H-NMR analysis showed apurity of 97.0% wt. in the desired catalyst together with a 3.0% wt. ofstarting ligand. Yield=64.4% (2.22 g).

[0170]¹NMR (C₆D₆, δ, ppm): −0.02 (q, 3H, Ti—CH₃, J=0.36 Hz); 0.07 (q,3H, Ti—CH₃, J=0.36 Hz); 0.55 (s, 3H, Si—CH₃); 0.74 (s, 3H, Si—CH₃); 1.39(s, 9H, t-Bu); 2.43 (s, 3H, CH₃); 3.10 (s, 3H, N—CH₃); 6.91 (d, 1H,J=8.31 Hz); 7.02 (ddd, 1H, J=8.61, 6.87, 1.17 Hz); 7.13 (dq, 1H, J=8.31,1.57, 0.59 Hz); 7.31 (ddd, 1H, J=8.26, 6.87, 0.96 Hz); 7.80 (dt, 1H,J=8.61, 0.96 Hz); 7.77-7.79 (m, 1H, Ar); 7.92 (dt, 1H, J=8.26, 1.17 Hz).

[0171]¹³C-NMR (C₆D₆, δ, ppm): 6.91 (C-Si); 7.37 (C-Si); 21.66 (CH₃);33.01 (N—CH₃); 34.62 (t-Bu); 55.56 (C-Ti); 57.24 (C-Ti); 68.74 (C-t-Bu); 109.43 (CH); 120.76 (CM); 124.17 (CH); 124.27 (CH); 125.22 (CH);125.76 (CH); 128.44 (CH).

[0172] m/z (%) by “direct insertion probe” technique: 439 (32) [M⁺+1];422 (100); 407 (26).

EXAMPLE 2

[0173] Synthesis ofdimethylsilyl(tert-butylamido)(N-methyl-2-methoxy-5,6-dihydroindeno[2,1-b]indol-6-yl)dimethyltitanium (B-2)

[0174] (a) Synthesis of 2-methoxy-5,6-dihydroindeno[2,1-b]indole

[0175] 8.21 g of 2-indanone (Aldrich, 98%, Mw=132.16, 60.88 mmol), 40 mLof isopropanol, 10.84 g of p-methoxyphenylhydrazin hydrochloride(Aldrich, 98%, Mw=174.63, 60.83 mmol) were charged at room temperaturein a 250 mL flask equipped with magnetic stirrer. The slurry was broughtto reflux (82° C.), (a black slurry was obtained), and kept at refluxfor 1 hour. The dark brown viscous suspension was then cooled to roomtemperature; 200 mL of water saturated with NaHCO₃ were added into thereactor (final pH ca. 7.5-8), the resulting mixture was filtered and theresidue washed with plenty of water. The dark green solid on the filterwas dried in vacuo at 70° C. for 4 hours (14 g, 98.9% pure by GC, 96.7%yield of pure product).

[0176]¹H-NMR (CDCl₃, δ, ppm): 3.69 (s, 2H, CH₂); 3.93 (s, 3H, O—CH₃);6.83-7.64 (m, 7H, Ar); 8.14 (bs, 1H, N—H).

[0177] (b) Synthesis ofN-methyl-2-methoxy-5,6-dihydroindeno[2,1-b]indole

[0178] 7.53 g of 2-methoxy-5,6-dihydroindeno[2,1-b]indole, obtained asreported above, (Mw=235.29, purity of 98.9%, 31.65 mmol) were dissolvedin 60 mL of 1,3-dioxolane (Aldrich) at room temperature. 3.6 g oftert-BuOK (Fluka, Mw=112.22, 31.90 mmol) were added: the solutionchanged color from green to dark brown, and was stirred at roomtemperature for 10 min. Then 1.96 mL of MeI (Mw 141.94, d=2.280, 31.50mmol) were added. After 10 min of stirring, a solid started forming.Stirring was continued for 1 hour, then the mixture was poured intowater containing 5 g of NH₄Cl. The formed solid was isolated byfiltration, the brown residue was dried in vacuo to obtain 7.85 g ofmicrocrystalline brown solid: GC purity 85.8%, 85.2% yield of pureproduct.

[0179]¹H-NMR (CDCl₃, δ, ppm): 3.65 (s, 2H, CH₂); 3.75 (s, 3H, N—CH₃);3.93 (s, 3H, O—CH₃); 6.85-7.61 (m, 7H, Ar).

[0180] (c) Synthesis ofchlorodimethyl(N-methyl-2-methoxy-5,6-dihydroindeno[2,1-b]indol-6-yl)silane

[0181] 3.4 mL of a 2.5 M solution of n-BuLi in hexane (8.50 mmol) wereadded dropwise to a solution of 2.22 g ofN-methyl-2-methoxy-5,6-dihydroindeno[2,1-b]indole, obtained as reportedabove, (Mw=249.32, purity 85.8%, 7.64 mmol; indenoindole: n-BuLi=1:1.1)in 50 mL of THF, previously cooled to −78° C. At the end of theaddition, the brown solution was allowed to warm up to room temperatureand stirred for 5 hours. Then it was cooled again to −78° C. and addeddropwise to a solution of dichlorodimethylsilane (Mw=129.06, d=1.064,0.92 mL, 7.64 mmol; indenoindole: Me₂SiCl₂=1:1) in 20 mL of THF,previously cooled to −78° C. At the end of the addition, the dark brownsolution was allowed to warm up to room temperature and stirredovernight. The solvents were evaporated under reduced pressure to givethe desired product, containing few by-products, in the form of a brownsticky solid; this product was used in the following step withoutfurther purification.

[0182] d) Synthesis of6-[dimethylsilyl(tert-butylamino)]N-methyl-2-methoxy-5,6-dihydroindeno[2,1-b]indole

[0183] 3.25 g of crudechlorodimethyl(N-methyl-2-methoxy-5,6-dihydroindeno[2,1-b]indol-6-yl)silane(Mw=341.91, 9.50 mmol), obtained as reported above, were dissolved in 50mL of toluene and added at −78° C. to a solution of t-BuNH₂ (2.3 mL,Mw=73.14, d=0.696, 21.89 mmol) in 20 mL of toluene. At the end of theaddition, the reaction mixture was allowed to warm up to roomtemperature and stirred overnight to give a brown suspension, which wasfiltered to remove the ammonium salt formed. The filtrate wasconcentrated under vacuum to give 2.18 g of the desired product as abrown sticky solid (raw yield=60.6%). This product was used in the nextstep without further purification.

[0184]¹H-NMR (CDCl₃, δ, ppm): −0.14 (s, 3H, Si—CH₃); −0.02 (s, 3H,Si—CH₃); 1.23 (s, 9H, t-Bu); 3.86 (s, 3H, N—CH₃); 3.926 (s, 1H, CH);3.934 (s, 3H, O—CH₃); 6.80-7.70 (m, 7H, Ar).

[0185] The fraction insoluble in toluene was extracted with 30 mL ofCH₂Cl₂ and 0.58 g of the by-productbis(N-methyl-2-methoxy-5,6-dihydroindeno[2,1-b]indol-6-yl)dimethylsilane, formed in the previous step, were isolated as a light brownpowder (13.7% yield towards startingN-methyl-2-methoxy-5,6-dihydroindeno[2,1 -b]indole).

[0186]¹H-NMR (CDCl₃, δ, ppm): −0.23 (s, 6H, Si—CH₃); 3.35 (s, 6H,N—CH₃); 3.91 (s, 6H, O—CH₃); 3.93 (s, 2H, CH); 6.82-7.63 (m, 14H, Ar).

[0187] (e) Synthesis ofdimethylsilyl(tert-butylamido)(N-methyl-2-methoxy-5,6-dihydroindeno[2,1-b]indol-6yl)dimethyl titanium

[0188] 15.6 mL of a 1.6 M solution of MeLi in diethylether (24.96 mmol)were added dropwise at room temperature to a solution of 2.18 g of6-[dimethylsilyl(tert-butylamino)]N-methyl-2-methoxy-5,6-dihydroindeno[2,1-b]indole(Mw=378.58, 5.76 mmol), obtained as reported above, in 45 mL of Et₂O.The reaction mixture was stirred for 5 hours at room temperature withfinal formation of a dark brown suspension. Then 0.65 mL of TiCl₄(Mw=189.71, d=1.730, 5.93 mmol) in 20 mL of pentane were slowly added atroom temperature, and the resulting mixture was stirred overnight. Thesolvents were removed under reduced pressure to give a black solid,which was extracted with 35 mL of toluene. The extract was concentratedyielding 1.16 g of the target product as a brown powder (rawyield=44.3%).

[0189]¹H-NMR (C₆D₆, δ, ppm): −0.01 (s, 3H, Ti—CH₃); 0.04 (s, 3H,Ti—CH₃); 0.55 (s, 3H, Si—CH₃); 0.74 (s, 3H, Si—CH₃); 1.40 (s, 9H, t-Bu);3.09 (s, 3H, N—CH₃); 3.55 (s, 3H, O—CH₃); 6.82-7.92 (m, 711, Ar).

EXAMPLE 3

[0190] synthesis ofdimethylsilyl(tert-butylamido)(N-methyl-2-methyl-1,8-dihydroindeno[2,1-b]pyrrol-6-yl)dimethyltitanium (B-3)

[0191] (a) N-methyl-2-methyl-1,8-dihydroindeno[2,1-b]pyrrole wasprepared according to the protocol described in Patent Application WO99/24446.

[0192] (b) Synthesis of8-[dimethylsilyl(tert-butylamino)]N-methyl-2-methyl-1,8-dihydroindeno[2,1-b]pyrrole

[0193] 18 mL of 1.6 M solution of BuLi (28.8 mmol) in hexane was addeddropwise to a solution of 3.5 g of N-Me-2-Me-indenopyrrole (19 mmol) in60 mL of ether at −30° C. At the end of the addition the solution wasallowed to warm up to room temperature and stirred for 4 hours. Then itwas cooled again to −30 ° C. and treated with 5 mL of Me₂SiCl₂ (42 mmol)in 5 mL of ether. The mixture was allowed to warm up to room temperatureand stirred overnight. The resulting suspension was filtered, thesolvent was evaporated in vacuum. The crude product was dissolved in 50mL of ether and then was treated dropwise with 17.5 mL (167 mmol) oft-butylamine at −20° C. The resulting mixture was allowed to warm up toroom temperature and then stirred overnight. The solution was isolatedby filtration and the solvent was evaporated to give the silyl-amine asa reddish-brown oil. Yield 4.67 g (83%).

[0194]¹H NMR (toluene-d⁸): 7.48 (d, 1H); 7.44 (d, 1H); 7.23 (t, 1H);7.05(t, 1H); 6.18 (1H); 3.12 (s, 3H); 2.15 (s, 3H); 1.02 (s, 9H); −0.11(s, 3H); −0.12 (s, 3H).

[0195] (c) Synthesis ofdimethylsilyl(tert-butylamido)(N-methyl-2-methyl-1,8-dihydroindeno[2,1-b]pyrrol-6-yl)dimethyl titanium

[0196] 49 mL of a 1.33 M solution of MeLi in diethyl ether (65.2 mmol)were added dropwise at −20° C. to a solution of 4.15 g of8-[dimethylsilyl(tert-butylamino)]-N-methyl-2-methyl-indenopyrrole (14mmol) in 60 mL of ether. The reaction mixture was stirred overnight andthen was cooled to −30° C. and was treated with 1.54 mL of TiCl₄ (14mmol) in 60 mL of hexane. The resulting black mixture was stirredovernight, then it was evaporated and added with 60 mL of toluene. Thenthe reaction mixture was evaporated and the residue was extracted twicewith 50 mL of toluene. The resulting solution was evaporated to a volumeof 15 mL and kept at room temperature for 15 hours. Red crystals wereisolated, washed twice with 10 mL of cooled pentane and dried. Yield 2.1g.

[0197]¹H NMR (toluene-d⁸): 7.68 (d, 1H); 7.61 (d, 1H); 7.20 (dd, 1H);6.94 (dd, 1H); 6.13 (s, 1H); 2.88 (s, 3H); 1.98 (s, 3H); 1.41 (s, 9H);0.73 (s, 3H); 0.51 (s, 3H); 0.05 (s, 3H); −0.04 (s, 3H)

EXAMPLE 4

[0198] synthesis ofdimethylsilyl(tert-butylamido)(N-ethyl-5,6-dihydroindeno[2,1-b]indol-6-yl)dimethyltitanium (B-4)

[0199] (a) Synthesis of 5,6-dihydroindeno[2,1-b]indole

[0200] In a 1-L flask were charged 36.55 g of 2-indanone (Aldrich,Mw=−132.16, 276.6 mmol), 40.00 g of phenyl-hydrazine hydrochloride(Aldrich, 99%, Mw=144.61, 276.6 mmol) and 0.3 L of i-PrOH. Thesuspension was warmed to 80° C. in about 30 minutes and the slurrychanged color from yellow to dark brown under stirring. The reactionmixture was stirred at 80° C. for 1.5 hours and then was cooled to roomtemperature in about 30 minutes. The slurry was siphoned into 1.0 L ofwater containing 34.85 g of NaHCO₃, thus obtaining a fine dispersion ofa green product (no heat evolution was observed). The slurry was thenfiltered on a G4 frit, washed with water, dried in air under moderatevacuum for 24 h until to achieve constant weight.

[0201] 52.81 g of the target product as a green powder were obtainedwith a yield of 92.8% (purity of 99.8% by G.C.)

[0202]¹H-NMR (CDCl₃, δ, ppm): 3.72 (s, 2H, CH₂); 7.12 (td, 1H, H8,J=7.48, 1.17 Hz); 7.16-7.29 (m, 2H, H2, H3); 7.31-7.39 (m, 2H, H1, H9);7.42 (dt, 1H, H7, J=7.24 Hz); 7.66 (dt, 1H, H10, J=7.48 Hz); 7.85-7.89(m, 1H, H4); 8.26 (bs, 1H, N—H).

[0203]¹³C-NMR (CDCl₃, δ, ppm): 31.51 (CH₂); 112.18 (C—H1); 118.77(C—H10); 119.56 (C—H4); 120.73, 121.84 (C—H2, C—H3); 122.47 (C10c);122.91 (C—H8); 125.05 (C—H7); 127.38 (C—H9); 140.32 (C10b); 140.93(C4a); 142.88 (C6a,10a); 146.44 (C5a).

[0204] (b) Synthesis of N-ethyl-5,6-dihydroindeno[2,1-b]indole

[0205] 15.00 g of 5,6-dihydroindeno[2,1-b]indole (99.8% by G.C.,Mw=205.26, 73.1 mmol) were dissolved into 200 mL of 1,3-dioxolane(Aldrich) at room temperature in a 0.5-L flask. 8.28 g of t-BuOK (Fluka,99%, Mw=112.22, 73.1 mmol) were added and the reaction mixture turnedfrom a green suspension to a brown solution. After 30 min stirring atroom temperature, 5.51 mL of EtBr (Fluka, 99%, Mw=108.97, d=1.46, 73.1mmol) were added, obtaining a brown suspension. Stirring was continuedfor 2 hours, then the reaction mixture was poured into water containing8 g of NH₄Cl (Carlo Erba RPE, purity 99.5%). After two hours stirring,the green-brown suspension was filtered on a G4 frit, the solid dried inair under moderate vacuum to give a green powder (8.98 g), which wasanalyzed by ¹H NMR. Purity 98.9% wt. by ¹H NMR (yield=52.1%).

[0206]¹H-NMR (CDCl₃, δ, ppm): 1.48 (t, 3H, CH₃, J=7.26 Hz); 3.73 (s, 2H,CH₂); 4.24 (q, 2H, CH₂, J=7.26 Hz); 7.04-7.90 (m, 8H, Ar).

[0207] (c) Synthesis of (tert-butylamino)dimethylchlorosilane

[0208] 15.95 mL of Me₂SiC₂ (Mw=129.06, 99%, d=1.064, 130.21 mmol) in 20mL of Et₂O were added dropwise at 0° C. to a solution of 20.41 g oft-BuNH₂ (Mw=73.14, 98%, d=0.696, 273.45 mmol, t-BuNH₂: Me₂SiCl₂=2.1:1)in 40 mL of Et₂O. The resulting milky suspension was allowed to warn upto room temperature and stirred for 30 min. The solvent was removed andthe residue extracted with 50 mL of pentane, to give 13.76 g of acolorless oil, which by ¹H-NMR analysis appeared to be the targetproduct 83.7% wt. pure, together with 16.3% wt. ofdi(t-butylamino)dimethylsilane. The silylamine was used in thesubsequent step without further purification. Yield 53.4%.

[0209]¹H-NMR (CDCl₃, δ, ppm): 0.44 (s, 6H, Si—CH₃); 1.21 (s, 9H, t-Bu).

[0210] (d) Synthesis of6-[dimethylsilyl(tert-butylamino)]ethyl-5,6-dihydro indeno[2,1-b]indole

[0211] 8.02 mL of n-BuLi 2.5 M in hexane (20.04 mmol) were addeddropwise at 0° C. to a solution of 4.30 g ofN-ethyl-5,6-dihydroindeno[2,1-b]indole (Mw=233.31, purity 98.9%, 18.22mmol) in Et₂O. At the end of the addition, the reaction mixture wasallowed to warm up to room temperature and stirred for two hours. Thedark brown solution obtained was added at 0° C. to a solution of 4.32 gof (tert-butylamino)dimethylchlorosilane (Mw=165.74, purity 83.7% wt.,d=0.887, 21.86 mmol) in Et₂O. The final mixture was allowed to warm upto room temperature and stirred for three hours. Then the solvents wereevaporated under reduced pressure to give a residue (8.73 g) which wasextracted with 50 mL of toluene. The extract, a sticky brown solid (7.48g), was washed with pentane obtaining 4.32 g of a light brown powder,which was analyzed by ¹H-NMR. The ¹H-NMR analysis showed a purity of96.6% wt. in the desired ligand together with a 3.4% wt. of startingN-ethyl-5,6-dihydroindeno[2,1-b]indole. Yield=63.1%.

[0212]¹H-NMR (C₆D₆, δ, ppm): −0.23 (s, 3H, Si—CH₃); −0.01 (s, 3H,Si—CH₃); 0.41 (bs, 1H, NH); 0.99 (s+t, 12H, t-Bu+CH₃); 3.56 (s, 1H, CH);4.07 (m, 2H, CH₂); 7.15-8.07 (m, 8H, Ar).

[0213]¹H-NMR (CDCl₃, δ, ppm): −0.13 (s, 3H, Si—CH₃); 0.03 (s, 3H,Si—CH₃); 0.75 (bs, 1H, NH); 1.26 (s, 9H, t-Bu); 1.37 (t, 3H, CH₃, J=7.14Hz); 3.84 (s, 1H, CH); 4.50 (m, 2H, CH₂); 6.90-8.00 (m, 8H, Ar).

[0214] (e) Synthesis ofdimethylsilyl(tert-butylamido)(N-ethyl-5,6-dihydroindeno[2,1-b]indol-6-yl)dimethyltitanium

[0215] 16.13 mL of a 1.6 M solution of MeLi in diethylether (25.80 mmol)were added dropwise at 0° C. to a solution of 2.30 g of6-[dimethylsilyl(tert-butylamino)]N-ethyl-5,6-dihydroindeno[2,1-b]indole(Mw=362.60, 6.34 mmol), obtained as reported above, in 40 mL of Et₂O.The resulting dark brown suspension was allowed to warm up to roomtemperature and stirred for 3 hours. Then 0.70 mL of TiCl₄ (Mw=189.71,d=1.730, 6.34 mmol) in 4 mL of pentane were slowly added at roomtemperature and the resulting dark brown suspension stirred for 1 hour.The solvents were removed under reduced pressure and the residue (4.63g) was extracted with 50 mL of toluene. The extract (2.27 g of a stickydark brown powder) was washed with pentane and the residue dried givinga brown powder (1.7 g), which was analyzed by ¹H-NMR. The ¹H-NMRanalysis showed a purity of 97.6% wt. in the desired catalyst togetherwith a 2.4% wt. of starting ligand. Yield=79.7%.

[0216]¹H-NMR (C₆D₆, δ, ppm): −0.002 (q, 3H, Ti—CH₃, J=0.41 Hz); 0.09 (q,3H, Ti—CH₃, J=0.41 Hz); 0.61 (s, 3H, Si—CH₃); 0.73 (s, 3H, Si—CH₃); 1.05(t, 3H, CH₃, J=7.26); 1.41 (s, 9H, t-Bu); 3.78 (q, 2H, CH₂, J=7.26 Hz);6.98-7.06 (m, 2H, H3, H8); 7.24-7.33 (m, 3H, H1, H4 and H9); 7.80 (dt,1H, J=8.67 Hz, H7); 7.88-7.93 (m, 2H, H2, H10).

[0217]¹³C-NMR (C₆D₆, δ, ppm): 6.62 (Si—CH₃); 7.63 (Si—CH₃); 14.48 (CH₃);34.51 (t-Bu); 40.00 (CH₂); 56.90 (Ti—CH₃); 57.01 (Ti—CH₃); 57.81(C-t-Bu); 67.98 (C-Si); 109.81 (C—H3); 114.56 (C—H10c); 120.48 (C—H1);120.59 (C—H2); 123.67 (C-10a); 124.08 (C—H10); 124.32 (C—H8); 124.49(C—H4); 125.27 (C—H9); 128.62 (C—H7); 134.89 (C6a); 145.50 (C4a); 147.34(C5a).

EXAMPLE 5

[0218] Synthesis ofdimethylsilyl(tert-butylamido)(2,5-dimethyl-7H-thieno[3′,2′:3,4]cyclopenta[1,2-b]thiophen-7-yl)dimethyl titanium (A-1).

[0219] a)Chloro(2,5-dimethyl-7H-thieno[3′,2′:3,4]cyclopenta[1,2-b]thiophen-7-yl)dimethylsilane.

[0220] A suspension of 4.13 g (20 mmol)2,5-dimethyl-7H-cyclopenta[1,2-b:4,3-b′]-dithiophene in 80 ml ether wastreated dropwise with 15 ml (24 mmol, 20% excess) 1.6M BuLi in hexane at−40° C. under stirring. The mixture was stirred for 3 h, and thentreated with 4.82 ml (40 mmol) Me₂SiCl₂ in 10 ml Et₂O. The precipitatewas filtered and used without further purification. Yield 4,84 g (81%),taking into consideration the presence of LiCl (1,02 g, 24 mmol).

[0221]¹H NMR (CDCl₃, 30° C.) δ: 6.85 (q, 2H), 3.93 (s, 1H), 2.57 (bs,6H), 0.25 (s, 6H).

[0222] b)N-(tert-Butyl)(2,5-dimethyl-7H-thieno[3′,2′:3,4]cyclopenta[1,2-b]thiophen-7-yl)dimethylsilanamine.

[0223] A solution of 2.12 ml (20 mmol) tert-butylamine in 70 ml etherwas treated dropwise with 12.5 ml (20 mmol) 1.6M BuLi in hexane at −30°C. The reaction mixture was stirred at r.t. for 3 h and the resultingsuspension was treated with a solution of 4.84 g (16.2 mmol)chloro(2,5-dimethyl-7H-thieno[3′,2′:3,4]cyclopenta[1,2-b]thiophen-7-yl)dimethylsilanein 30 ml ether at −70° C. The resulting suspension was allowed to warmto r.t. and was stirred overnight. The solution was separated from LiCland evaporated. Yield 4.47 g (82%) of brown solid that was used withoutfurther purification.

[0224]¹H NMR (CDCl₃, 30° C.) δ: 6.85 (q, 2H), 3.80 (s, 1H), 2.58 (bs,6H), 1.31 (s,9H), 0.05 (s, 6H).

[0225] c)Me₂Si(t-BuN)(2,5-dimethyl-7H-thieno[3′,2′:3,4]cyclopenta[1,2-b]thiophen-7-yl)TiMe₂.

[0226] To a solution of 1.93 g (5.7 mmol)N-(tert-butyl)(2,5-dimethyl-7H-thieno[3′,2′:3,4]cyclopenta[1,2-b]thiophen-7-yl)dimethylsilanaminein 30 ml ether 23 ml (28.7 mmol) 1.2M MeLi in ether was added at −40° C.under stirring. Then the reaction mixture was stirred under reflux for 3h. The resulting mixture was cooled to −60° C. and the solution of 0.63ml (5.7 mmol) TiCl₄ in 30 ml hexane was added. The mixture was allowedto warm and was stirred overnight The resulting mixture was evaporated,the residue was extracted with hexane (3 times with 50 ml). The hexanesolution was concentrated to a volume of 10 ml and kept for 10 hours atr.t. The crystalline product was separated from the mother solution,washed twice with cold pentane and dried. Yield 0.27 g (11%) of dark redcrystals.

[0227]¹H NMR (C₇D₈, 30° C.) δ: 6.76 (q, 2H), 2.20 (d, 6H), 1.49 (s, 9H),0.56 (s, 6H), 0.36 (s, 6H).

[0228]¹³C NMR (C₇D₈, 30° C.) δ: 146.51, 139.67, 133.08, 116.65, 78.16,58.00, 56.82, 34.56,16.29 3.21.

EXAMPLE 6

[0229] Synthesis of dimethylsilyl(tert-butylamido)(indenyl)dimethyltitanium (C-3)

[0230] 11.3 mL of a 1.6 M solution of methylithium in diethyl ether(18.04 mmoles) were slowly added at −78° C. to a solution of 1.08 gram(4.40 mmoles) of IndMe₂SiNH^(t)Bu in 23 mL of diethyl ether. During theaddition an increasing turbidity develops with final formation of ayellow suspension. This mixture was allowed to warm to room temperatureand stirred for two hours.

[0231] 0.5 mL of TiCl₄ (4,40 mmoles) were diluted in 23 mL of pentane.This solution was added very slowly and cautiously to the Li saltsuspension in diethyl ether at room temperature. The resulting darksuspension was stirred at room temperature overnight. The reactionmixture was then brought to dryness under reduced pressure. The darksolid was extracted with 60 mL of toluene and then the filtrate wasevaporated to dryness under reduced pressure to give 0.99 g (70% yield)of a gray-black solid. ¹H NMR confirms formation of[Me₂Si(Ind)(t-BuN)]TiMe₂.

[0232]¹H NMR (C₆D₆, δ, ppm): −0.15 (q, J=0.48 Hz, 3H, Ti—CH₃), 0.36 (s,3H, Si—CH₃), 0.53 (s, 3H, Si—CH₃), 0.82 (q, J=0.48 Hz, 3H, Ti—CH₃), 1.44(s, 9H, t-Bu); 6.05 (d, J=3.21 Hz, 1H, Cp-H2); 6.88 (ddd, J=8.50, 6.64,1.04 Hz, 1H, Ar-H6); 7.01 (dd, J=3.21, 0.83 Hz, 1H, Cp-H3); 7.07 (ddd,J=8.50, 6.64, 1.04 Hz, 1H, Ar-H5); 7.46 (dq, J=8.50, 1.04 Hz, 1H,Ar-H7); 7.48 (dt, J=8.50, 1.04 Hz, 1H, Ar-H4).

EXAMPLE 7

[0233] Synthesis ofdimethylsilyl(tert-butylamido)(2-methyl-indenyl)dimethyl titanium (C-4)

[0234] The complex dimethylsilyl(tert-butylamido)(2-methyl-1-indenyl)dimethyl titanium was prepared from the corresponding ligand in 71%, byusing the same procedure.

[0235] (a) Synthesis of (2-Me-Ind)SiMe₂(^(t)BuNH)

[0236] 5.02 g of (2-Me Ind)SiMe₂Cl (25.53 mmol) in Et₂O were added at 0°C. to a solution of ^(t)BuNH₂ (56.16 mmol) to give a yellow slurry. Themixture was stirred at room temperature for 16 h. The solvents wereevaporated under reduced pressure, and the product extracted withtoluene to give, after filtration and evaporation of the solvent, 5.52 gof an orange oil. ¹H NMR analysis shows the presence of the two isomers(allylic, 60%, vinylic, 40%).

[0237] Yield 83.4%.

[0238]¹H-NMR (C₆D₆, δ, ppm), allylic isomer: −0.09 (s, 3H, Si—CH₃); 0.11(s, 3H, Si—CH₃); 1.02 (s, 9H, ^(t)Bu); 2.14 (s, 3H, CH₃); 3.21 (s, 1H,C—H); 6.52 (s, 1H, C—H); vinylic isomer: 0.46 (s, 6H, Si—CH₃); 1.1 (s,9H, ^(t)Bu); 2.06 (s, 3H, CH₃); 3.05 (s, 2H, CH₂); both isomers:6.98-7.82 (m, 8H, Ar);

[0239] (b) Synthesis of Me₂Si(2-Me-Ind)(^(t)BuN)TiMe₂

[0240] 25 mL of MeLi 1.6 M in Et₂O (40 mmol) were added at 0 ° C to asolution of 2.53 g of (2-Me Ind)SiMe₂(^(t)BuNH) (9.75 mmol), after 1.5 hstirring at room temperature were added 1.07 mL of TiCl₄ in pentane(9.75 mmol). After 2 h the solvents were removed under reduced pressure,the mixture taken up in 50 mL of toluene, stirred 30 min, and filteredto give, after evaporation of the solvent, 2.68 g of dark brown powder.The powder was taken up in pentane, filtered, and the filtrated broughtto dryness under reduced pressure to give 2.31 g of ochra powder. Yield70.6%.

[0241]¹H-NMR (C₆D₆, δ, ppm): −0.11 (q, 3H, J=0.48 Hz, Ti—CH₃); 0.46 (bs,3H, Si—CH₃); 0.56 (bs, 3H, Si—CH₃); 0.85 (q, 3H, J=0.48 Hz, Ti—CH₃);1.47 (s, 9H, ^(t)Bu); 1.99 (s, 3H, CH₃); 6.76 (bs, 1H, H3); 6.89 (ddd,1H, H6, J=8.41, 6.77, 1.08 Hz); 7.07 (ddd, 1H, H5, J=8.41, 6.77, 1.08Hz); 7.44 (dt, 1H, H4, J=8.41, 1.08 Hz); 7.51 (dq, 1H, H7, J=8.41, 1.08Hz).

[0242]¹³C-NMR (C₆D₆, δ, ppm): 5.30 (C-Si); 5.55 (C-Si); 17.98 (CH₃);33.85 ((CH₃)₃); 50.82 (C-Ti); 56.57 (C-Ti); 57.55 (C-^(t)Bu); 115.64(C—H3); 124.72 (C—H6); 124.9 (C—H4); 125.17 (C—H5); 127.81 (C—H7);131.57 (C—C3a); 133.82 (C—C7a); 140.97 (C—CH₃).

EXAMPLE 8

[0243] Preparation of the supported catalyst

[0244] Polyethylene (PE) used as carrier has particles diameter of250-300 μm, porosity measured with Mercury porosimeter technique (MA17302) is about 50% V/V, the surface area is 5.6 m²/g and the averagediameter of pores is 8923 Å.

[0245] Impregnation

[0246] The apparatus used for the supportation is a glass cylindricalvessel, equipped with a vacuum pump, a dosing pump for the feeding ofthe catalytic solution on the carrier and a stirrer to allow a goodmixing during the impregnation step. The preparation of the supportedcatalysts is carried out under nitrogen flow at room temperature.

[0247] 5 g of the PE carrier described above is loaded into the vesseland mechanically stirred under nitrogen flow, 3 ml of a MAO solution(Witco, 100 g/l in toluene) is dosed in a single addition step on theprepolymer to scavenge residual impurities, in order to reach theincipient wetness. The solvent is then evaporated under vacuum.

[0248] The catalytic solution is prepared by dissolving 17 mg of B-4 in9 ml of the same MAO solution, with the aim of achieving an Al/Ti=400mol/mol. After stirring for 15 minutes, this solution is added to thecarrier in 3 aliquots; after each addition, once reached the incipientwetness, the solvent is evaporated under vacuum.

[0249] The analysis of the obtained supported catalysts are Al=7.3%,Ti=0.03%.

[0250] POLYMERIZATION TESTS

[0251] Batch polymerizations were carried out in a 1-L or 4.25-Lstainless-steel stirred reactor. The reactor was purified by washingwith a hexane solution of TIBA (Al(i-Bu)₃), and then dried by purgingwith propylene at 80° C. for one hour. The catalyst/cocatalyst mixturewas prepared by dissolving the Ti complex in the required amount ofMAO/toluene solution, and aged 10 min.

EXAMPLES 9-11

[0252] Propylene polymerization

[0253] MAO (commercial product by Witco, 10% w/w in toluene, 1.7 M inAl) was used as received. The catalyst system was prepared by dissolvingthe amount ofdimethylsilyl(tert-butylamido)(N-methyl-2-methyl-5,6-dihydroindeno[2,1-b]indol-6-yl)dimethyltitanium (B-1) prepared according example 1, first synthetic route, asreported in Table 1, with the amount of MAO reported in Table 1; theobtained solution was stirred for 10 minutes at room temperature, beforebeing injected into the autoclave.

[0254] 1 mmol of Al(i-Bu)₃ (TIBA) (as a 1 M solution in hexane) and 300g of propylene were charged, at room temperature, in a 1-L jacketedstainless-steel autoclave, equipped with magnetically driven stirrer anda 35-mL stainless-steel vial, connected to a thermostat for temperaturecontrol, previously purified by washing with an Al(i-Bu)₃ solution inhexane and dried at 50° C. in a stream of propylene. The autoclave wasthen thermostatted at 2° C. below the polymerization temperature and thecatalyst system, prepared as reported above, was injected in theautoclave by means of nitrogen pressure through the stainless-steelvial. The temperature was rapidly raised to the polymerizationtemperature, as indicated in Table 1, and the polymerization was carriedout at constant temperature, for the time reported in Table 1.

[0255] After venting the unreacted monomer and cooling the reactor toroom temperature, the polymer was dried under reduced pressure, at 60°C.

[0256] The polymerization data and the characterization data of theobtained polymers are reported in Table 1.

[0257] The obtained results demonstrate that the titanium complexesaccording to the present invention may give high molecular weightamorphous polypropylene.

EXAMPLE 12

[0258] Propylene polymerization

[0259] Propylene polymerization was carried out according to theprocedure reported in Examples 9-11, with the difference that B-1obtained according example 1, second synthetic route, was used ascatalyst.

[0260] Polymerization data, yields and characteristics of the obtainedpolymer are reported in Table 1.

EXAMPLE 13

[0261] Influence of hydrogen

[0262] In order to evaluate the influence of hydrogen on the molecularweight of the obtained polymers, propylene polymerization was carriedout according to the procedure reported in Examples 9-11, with the onlydifference of introducing 100 mL hydrogen before adding propylene.

[0263] Polymerization data are reported in Table 1.

[0264] The obtained results confirm that the titanium complexesaccording to the present invention are sensitive to hydrogen as amolecular weight regulator.

EXAMPLE 14

[0265] Propylene/ethylene copolymerization

[0266] Propylene polymerization was carried out according to theprocedure reported in Examples 9-11, with the only difference that,before charging the amount of propylene reported in Table 1, 4.1 g ofethylene were charged in the autoclave.

[0267] The resulting copolymer has an ethylene content of 0.8% wt (¹³CNMR), the other polymerization data, yields and characteristics of theobtained copolymer are reported in Table 1.

[0268] The obtained results demonstrate a good activity of the titaniumcomplexes of the invention in propylene/ethylene copolymerization; theinsertion of small amounts of ethylene in propylene polymers may serveto regulate the molecular weight of the final polymers, at the same timewithout negatively affecting intrinsic viscosity values and the yield ofthe process. The use of low amounts of ethylene in propylenepolymerization process, according to the present invention, makes itpossible to regulate the molecular weight of the obtained polymers.

EXAMPLE 15

[0269] Propylene homopolymerization

[0270] 1200 g of liquid propylene were loaded into a 4.25-Lstainless-steel stirred reactor at 30° C., followed by 1 mmol of TIBA inhexane used as a scavenger. The temperature of the reactor was thenraised up to 60° C.

[0271] The polymerization was started by injecting 2.1 mL of a toluenesolution of MAO (ca. 6 mmol of Al) containing 1.4 mg of the B-3 into theautoclave at 60° C., by means of nitrogen overpressure, then thetemperature was maintained at 60° C. for 37 min. The polymerization wasstopped by venting and cooling the reactor.

[0272] The soft, non-sticky, amorphous product obtained was 530 g,corresponding to a yield of about 600 kg/(g_(cat)×h). The properties ofthe polymer are:

[0273] I.V.=3.65 dL/g, no melting point (DSC), rr=72.16, rrrr=51.7 (¹³CNMR).

[0274] Polymerization data, yields and characteristics of the obtainedpolymer are summarized in Table 1

EXAMPLE 16

[0275] Propylene homopolymerization.

[0276] 2 mL of a hexane solution of TIBA (1 mmol of TIBA in used as ascavenger), 271 g of liquid propylene were loaded into a 1-Lstainless-steel stirred reactor at 30° C. The temperature of the reactorwas then raised up to 70° C.

[0277] The polymerization was started by injecting 3 mL of a toluenesolution of MAO (0.64 mmol of Al, MAO/Zr=500) containing 0.5 mg of B-3into the autoclave at 70° C., by means of nitrogen overpressure, thenthe temperature was maintained at 70° C. for 60 min. The polymerizationwas stopped by pressurizing CO, venting and cooling the reactor.

[0278] The soft, non-sticky, amorphous product obtained was 53 g,corresponding to a yield of about 106 kg/(g_(cat)×h). The properties ofthe polymer are:

[0279] I.V.=4.92 dL/g, no melting point (DSC).

[0280] Polymerization data, yields and characteristics of the obtainedpolymer are summarized in Table 1.

EXAMPLE 17

[0281] Propylene/ethylene copolymerization.

[0282] 2 L of hexane were loaded into a 4.25-L stainless-steel stirredreactor at 30° C., followed by 2 mmol of TIBA in hexane used as ascavenger. 397 g of propylene and 38 g of ethylene were then pressurizedinto the reactor, and the temperature of the reactor was then raised upto 50° C., resulting in a pressure of 9.3 bar-g.

[0283] The polymerization was started by injecting 4.3 mL of a toluenesolution containing MAO (1.29 mmol of Al) and 0.5 mg of B-3 into theautoclave at 50° C., by means of nitrogen overpressure, then thetemperature was maintained at 50° C. and ethylene was continuously fedinto the reactor in order to maintain a constant pressure. After 7 g ofethylene were added in 23 min, the polymerization was stopped bypressurizing 1.5 L of CO into the reactor, venting and cooling thereactor. The propylene/ethylene copolymer was recovered from the hexanesolution by precipitation in acetone, followed by drying under reducedatmosphere at 70° C. for 4 hours.

[0284] 104 g of non-sticky, amorphous copolymer were obtained,corresponding to a yield of about 540 kg/(g_(cat)×h). The copolymercontains 20% by weight of ethylene (¹H NMR analysis), is fully amorphouswith T_(g)=−26° C., and has an intrinsic viscosity of 6.65 dL/g.

EXAMPLE 18

[0285] Propylene/butene copolymerization.

[0286] 2 mL of a hexane solution of TIBA (1 mmol of TIBA in used as ascavenger), 158 g of propylene and 154 g of 1-butene were loaded into a1-L stainless-steel stirred reactor at 30° C.

[0287] The temperature of the reactor was then raised up to 60° C. (15bar-g).

[0288] The polymerization was started by injecting 3 mL of a toluenesolution of MAO (ca. 2.6 mmol of Al) containing 1 mg of the B-3 into theautoclave at 60° C., by means of nitrogen overpressure, then thetemperature was maintained at 60° C. for 60 min. The polymerization wasstopped by pressurizing Co, venting and cooling the reactor.

[0289] The soft, non-sticky, amorphous product obtained was 13 g. Theproperties of the polymer are:

[0290] I.V.=0.9 dL/g, no melting point and T_(g)=−7° C., (DSC),butene=47 wt % (measured by ¹³C NMR).

EXAMPLE 19

[0291] Propylene/butene copolymerization

[0292] Example 18 was repeated at an Al/Zr ratio of 500, obtaining acopolymer with I.V.=2.11 dL/g.

EXAMPLE 20

[0293] Propylene polymerizations at 80° C.

[0294] Following the usual procedure, 1 mmol of TIBA and 585 g ofpropylene were charged in a 2 L reactor, then heated to 80° C. 1 mg ofB-3 was dissolved with 1.07 mL of a 10% MAO solution (1.82 mmol Al) intoluene and then diluted with toluene (total volume 3 mL), aged 10 minand injected into the reactor. The polymerization is stopped with COafter 60 min at 80° C. The results of polymer analysis are shown inTable 1.

EXAMPLE 21

[0295] Propylene polymerizations at 80° C.

[0296] Following the usual procedure, 1 mmol of TIBA and 585 g ofpropylene were charged in a 2 L reactor, then heated to 80° C. 0.5 mg ofB-3 was dissolved with 1.07 mL of a 10% MAO solution (1.82 mmol Al) intoluene and then diluted with toluene (total volume 3 mL), aged 10 minand injected into the reactor. The polymerization is stopped with COafter 60 min at 80° C. The results of polymer analysis are shown inTable 1.

EXAMPLES 22-23

[0297] Propylene polymerization was carried out according to theprocedure reported in Examples 9-11, with the difference that B-4 wasused as catalyst instead of B-1

[0298] Polymerization data, yields and characteristics of the obtainedpolymer are reported in Table 1.

EXAMPLES 24

[0299] Polymerization with supported catalysts

[0300] 1200 g of liquid propylene were loaded into a 4.25-Lstainless-steel stirred reactor at 30° C., followed by 1 mmol of TIBA inhexane used as a scavenger. 200 mL of hydrogen were added before thecatalyst. 650 mg of the solid catalyst prepared in example 8 was theninjected into the reactor by means of nitrogen overpressure through astainless-steel vial, and then the temperature of the reactor was raisedup to the polymerization temperature in 15 min.

[0301] After one hour, the polymerization was stopped by venting andcooling the reactor, and the amorphous product collected and dried.

[0302] Polymerization data, yields and characteristics of the obtainedpolymers are summarized in Table 1.

EXAMPLES 25

[0303] Propylene polymerizations at 80° C.

[0304] Following the usual procedure, 1 mmol of TIBA and 585 g ofpropylene were charged in a 2 L reactor, then heated to 80° C. 1.5 mg ofA-1 was dissolved with 1.07 mL of a 10% MAO solution (1.82 mmol A1) intoluene and then diluted with toluene (total volume 3 mL), aged 10 minand injected into the reactor. The polymerization is stopped with COafter 60 min at 80° C. 85 g of rubbery, amorphous polypropylene wererecovered, corresponding to a catalyst activity of 56.6kg_(PP)/(g_(cat)×h). The results of polymer analysis are shown in Table1.

COMPARATIVE EXAMPLES 26-28

[0305] Propylene polymerization was carried out according to theprocedure reported in Examples 9-11, with the difference thatdimethylsilyl(tert-butylamido)(tetramethylcyclopentadienyl) titaniumdichloride was used as catalyst instead of the titanium complex of theinvention.

[0306] Polymerization data, yields and characteristics of the obtainedpolymer are reported in Table 1.

[0307] The obtained result demonstrates that the titanium complexes ofthe invention are able to exert polymerization activities superior tothe one of constrained geometry catalysts known in the state of the art.

COMPARATIVE EXAMPLE 29

[0308] Propylene polymerization was carried out according to theprocedure reported in Example 9 with the difference thatdimethylsilyl(tert-butylamido)(tetramethylcyclopentadienyl) titaniumdichloride was used as catalyst instead of the titanium complex of theinvention mixture. Polymerization data are reported in Table 1.

COMPARATIVE EXAMPLE 30

[0309] Propylene/ethylene copolymerization was carried out according tothe procedure reported in Example 9 with the difference that 4.5 g ofethylene were added to the reactor before adding 288 g of propylene,dimethylsilyl(tert-butylamido)(tetramethylcyclopentadienyl) titaniumdichloride (obtained by Witco) was used as catalyst instead of thetitanium complex of the invention, and 15.7 g of ethylene were fed intothe reactor over the polymerization time of 1 hour in order to maintaina constant pressure of 25.6 bar-g (of which 0.3 bar are due tonitrogen). The resulting copolymer has an ethylene content of 4.5 % wt(¹³C NMR), the other polymerization data are reported in Table 1.

COMPARATIVE EXAMPLES 31-32

[0310] Propylene polymerization was carried out according to theprocedure reported in Examples 9-11, with the difference thatdimethylsilyl(tert-butylamido)(indenyl) titanium dimethyl was used ascatalyst instead of the titanium complex of the invention.

[0311] Polymerization data, yields and characteristics of the obtainedpolymer are reported in Table 1. The obtained result demonstrates thatthe titanium complexes of the invention are able to exert polymerizationactivities superior to the one of constrained geometry catalysts knownin the state of the art.

COMPARATIVE EXAMPLE 33

[0312] Propylene polymerization was carried out according to theprocedure reported in Examples 9-11, with the difference thatdimethylsilyl(tert-butylamido)(2-methyl-indenyl) titanium dimethyl wasused as catalyst instead of the titanium complex of the invention.

[0313] Polymerization data, yields and characteristics of the obtainedpolymer are reported in Table 1. The obtained result demonstrates thatthe titanium complexes of the invention are able to exert polymerizationactivities superior to the one of constrained geometry catalysts knownin the state of the art. TABLE 1 Ti mg of MAO/Ti T_(POL) Time ActivityI.V. tacticity (%) Ex. complex complex Molar ratio ° C. minKg_(PP)/g_(cat) dL/g rr rrrr 2,1  9 B-1 1 500 50 60 41.6 5.97 73.8 57.5<0.5 10 B-1 1 1000 60 30 49.4 3.14 72.4 53.3 <0.5 11 B-1   0.7 1000 7060 26.9 3.06 69.2 48.4 <0.5 12 B-1 1 500 70 60 37.9 4.69 — — — 13^(a))B-1 1 1000 60 60 12.2 1.84 — — — 14^(b)) B-1 1 1000 60 30 81.7 2.41 — —— 15^(c)) B-3   1.4 1000 60 37 530 3.65 72.2 51.7 0 16 B-3   0.5 500 7060 106 4.92 — — — 20 B-3 1 500 80 60 288 4.16 68.9 48.1 0 21 B-3   0.5500 80 60 320 5.01 70.2 50.69 0 22 B-4   0.3 1000 60 60 113 7.89 73.057.1 0.3 23 B-4   0.5 1000 70 60 106 5.96 72.8 54.1 0 24^(c)) B-4610^(f)) 60 60 0.28^(g)) 5.85 — — — 25 A-1   1.5 500 80 60 56.7 4.2533.4 10.6 0.5 26* C-1^(e)) 2 1000 60 60 29.5 3.56 50.2 25.3 1.3 27*C-1^(e)) 2 1000 70 60 31.5 2.58 — — — 28* C-1^(e)) 2 500 70 60 25.8 2.70— — — 29*^(a)) C-1^(e)) 2 1000 60 60 23.8 2.42 52.1 25.4 1.5 30*^(d))C-1^(e)) 2 1000 60 60 32.3 4.84 — — — 31* C-3 2 1000 60 60 12.7 1.12 — —— 32* C-3 2 500 70 60 7.1 0.92 — — — 33* C-4 1 1000 60 60 18.3 3.15 51.428.3 0.6

1. A process for producing substantially amorphous propylenehomopolymers or copolymers comprising contacting propylene, optionallyin the presence of one or more olefins selected from the groupconsisting of ethylene, alpha-olefins of formula CH₂═CHR′ wherein R′ isa linear or branched, C₂-C₁₀ alkyl or non conjugate diolefins containingup to 20 carbon atoms, under polymerization conditions with a catalystsystem comprising: A) a titanium complex of formula (I):

wherein: Ti is titanium; X is a nitrogen (N) or phosphorous (P) atom; Zis a C, Si or Ge atom; the groups R¹, equal to or different from eachother, are selected from the group consisting of hydrogen, linear orbranched, saturated or unsaturated C₁-C₂₀ alkyl, C₃-C₂₀ cycloalkyl,C₆-C₂₀ aryl, C₇-C₂₀ alkylaryl and C₇-C₂₀ arylalkyl optionally containingSi or heteroatoms belonging to groups 13 or 15-17 of the Periodic Tableof the Elements, or two R¹ groups form together a C₄-C₇ ring; Y¹ is anatom selected from the group consisting of NR⁷, oxygen (O), PR⁷ orsulfur (S), wherein the group R⁷ is selected from the group consistingof linear or branched, saturated or unsaturated, C₁-C₂₀ allyl, C₆-C₂₀aryl and C₇-C₂₀ arylalkyl radical; the groups R² and R³ equal to ordifferent from each other, are selected from the group consisting ofhydrogen, halogen, -R, -OR, -OCOR, -OSO₂CF₃, -SR, -NR₂ and -PR₂, whereinR is linear or branched, saturated or unsaturated C₁-C₂₀ allyl, C₃-C₂₀cycloalkyl, C₆-C₂₀ aryl, C₇-C₂₀ alkylaryl or C₇-C₂₀ arylalkyl radical;two R can also form a saturated or unsaturated C₄-C₇ ring, or R² and R³form a condensed aromatic or aliphatic C₄-C₇ ring that can besubstituted with one or more R⁹ groups, wherein R⁹ is selected from thegroup consisting of halogen, -R, -OR, -OCOR, -OSO₂CF₃, -SR, -NR₂ and-PR₂, wherein R has the meaning reported above, or two vicinal R⁹ groupsform together a condensed aromatic or aliphatic C₄-C₇ ring; the groupsR⁸, R⁴ and R⁵, equal to or different from each other, are selected fromthe group consisting of hydrogen, halogen, -R, -OR, -OCOR, -OSO₂CF₃,-SR, -NR₂ and -PR₂, wherein R has the meaning reported above, or R⁸ andR⁴, R⁴ and R⁵ or R⁵ and R⁸ form together a condensed C₄-C₇ ring that canbe substituted with one or more R groups; the group R⁶ is selected fromthe group consisting of a linear or branched, saturated or unsaturatedC₁-C₂₀ alkyl, C₆-C₂₀ aryl and C₇-C₂₀ arylalkyl radical, optionallycontaining heteroatoms belonging to groups 13 or 15-17 of the PeriodicTable of the Elements; the substituents L, equal to or different fromeach other, are monoanionic sigma ligands selected from the groupconsisting of hydrogen, halogen, -R, -OR, -OCOR, -OSO₂CF₃, -SR, -NR₂ and-PP₂, wherein R has the meaning reported above; Y² is selected from thegroup consisting of CR⁸ or Y¹; and m is 0 or 1; when the group Y² is aCR⁸ group m is 1 and the 6 membered ring formed is an aromatic benzenering; when Y² is different from CR⁸ m is 0 and the carbon atom bondingthe R⁴ group is directly bonded to the cyclopentadienyl ring and thering formed is a 5 membered ring; and (B) an activating cocatalyst. 2.The process according to claim 1 wherein the titanium complex hasformula (III)

wherein X, Z, Y¹, L, R¹, R², R³, R⁴, R⁵, R⁶ and R⁸ have the meaningreported in claim 1 with the proviso that R² and R³ do not form acondensed aromatic C₆ ring.
 3. The process according to claim 2 whereinin the titanium complex of formula (III) X is a nitrogen atom; thedivalent bridge >ZR¹ ₂ is preferably selected from the group consistingof dimethylsilyl diphenylsilyl, diethylsilyl, di-n-propylsilyl,di-isopropylsilyl, di-n-butyl-silyl, di-t-butyl-silyl, di-n-hexylsilyl,ethylmethylsilyl, n-hexylmethylsilyl, cyclopentamethylenesilyl,cyclotetramethylenesilyl, cyclotrimethylenesilyl, methylene,dimethylmethylene and diethylmethylene; Y¹ is N-methyl, N-ethyl orN-phenyl; R² is hydrogen, methyl, ethyl, propyl or phenyl; R³ ishydrogen methyl or phenyl; R⁴ and R⁸ are hydrogen, methyl; R⁵ ishydrogen, methoxy or tertbutyl; R⁶ is selected from the group consistingof methyl, ethyl, n-propyl, isopropyl, n-butyl, t-butyl, phenyl,p-n-butyl-phenyl, benzyl, cyclohexyl and cyclododecyl; the substituentsL, equal to or different from each other, are preferably halogen atoms,linear or branched, saturated or unsaturated C₇-C₂₀ alkylaryl, C₁-C₆alkyl groups or OR wherein R is defined as in claim
 1. 4. The processaccording to claim 1 wherein the titanium complex has formula (IV)

wherein X, Z, Y¹, L, R¹, R⁵, R⁶, R⁸, and R⁹ have the meaning reported inclaim 1 and k ranges from 0 to
 4. 5. The process according to claim 4wherein in the titanium complex of formula (IV) X is a nitrogen atom;the divalent bridge >ZR¹ ₂ is selected from the group consisting ofdimethylsilyl, diphenylsilyl, diethylsilyl, di-n-propylsilyl,di-isopropylsilyl, di-n-butyl-silyl, di-t-butyl-silyl, di-n-hexylsilyl,ethylmethylsilyl, n-hexylmethylsilyl, cyclopentamethylenesilyl,cyclotetramethylenesilyl, cyclotrimethylenesilyl, methylene,dimethylmethylene and diethylmethylene; Y¹ is N-methyl, N-ethyl orN-phenyl; k is 0 or 1 and R⁹ is 2-methyl, 2-tert-butyl, 2-methoxy; R⁶ isselected from the group consisting of methyl, ethyl, n-propyl,isopropyl, n-butyl, t-butyl, phenyl, p-n-butyl-phenyl, benzyl,cyclohexyl and cyclododecyl; R⁴, R⁵ and R⁸ are hydrogen atoms; thesubstituents L, equal to or different from each other, are halogen atomslinear or branched, saturated or unsaturated C₁-C₆ alkyl, C₇-C₂₀alkylaryl groups or OR wherein R is defined as in claim
 1. 6. Theprocess according to claim I wherein the titanium complex has formula(V)

wherein X, Z, L, Y¹, R¹, R², R³, R⁴, R⁵ and R⁶ have the meaning reportedin claim
 1. 7. The process according to claim 6 wherein in the titaniumcomplex of formula (V): X is a nitrogen atom; the divalent bridge >ZR¹ ₂is preferably selected from the group consisting of dimethylsilyl,diphenylsilyl, diethylsilyl, di-n-propylsilyl, di-isopropylsilyl,di-n-butyl-silyl, di-t-butyl-silyl, di-n-hexylsilyl, ethylmethylsilyl,n-hexylmethylsilyl, cyclopentamethylenesilyl, cyclotetramethylenesilyl,cyclotrimethylenesilyl, methylene, dimethylmethylene anddiethylmethylene; two Y¹ are the same group; R² is hydrogen, methyl,ethyl, propyl or phenyl; and R⁴ is hydrogen or R² and R³ form acondensed benzene ring that can be substituted with one or more Rgroups; R⁴ is hydrogen and R⁵ is hydrogen methyl, ethyl, propyl orphenyl or R⁴ and R⁵ form a condensed benzene ring that can besubstituted with one or more R groups; R⁶ is preferably selected fromthe group consisting of methyl, ethyl, n-propyl, isopropyl, n-butyl,t-butyl, phenyl, p-n-butyl-phenyl, benzyl, cyclohexyl and cyclododecyl;the substituents L, equal to or different from each other, arepreferably halogen atoms linear or branched, saturated or unsaturatedC₇-C₂₀ alkylaryl, C₁-C₆ allyl groups or OR wherein R is defined as inclaim
 1. 8. The process according to any of claims 1 to 7 wherein thecocatalyst is selected from the group consisting of alumoxanes orcompounds capable of forming an alkyl metallocene cation.
 9. The processaccording to any of claims 1 to 8 wherein the catalyst system issupported on an inert carrier.
 10. The process according to claim 9wherein the inert carrier is selected from the group consisting ofsilica, alumina, magnesium halides, olefin polymers or prepolymers. 11.The process according to claims 9 or 10 wherein the catalysts system issupported, by depositing the titanium complex (A), or the reactionproduct of the titanium complex (A) with the cocatalyst (B), or thecocatalyst (B) and successively the titanium complex (A), on the inertsupport.
 12. The process according to any of claims 1 to 11 wherein theprocess is carried out in gaseous phase.
 13. A titanium complex offormula (I):

wherein X, Z, L, Y¹, Y², m, R¹, R², R³, R⁴, R⁵, R⁶ and R⁸ have themeaning reported in claim
 1. 14. The titanium complex according to claim13 having formula (III):

wherein X, Z, Y¹, R¹, R², R³, R⁴, R⁵, R⁶ and R⁸ have the meaningreported in claims 2 or
 3. 15. The titanium complex according to claim13 having formula (IV):

wherein X, Z, Y¹, L, R¹, R⁴, R⁵, R⁶, R⁸, R⁹, and k have the meaningreported in claims 4 or
 5. 16. The titanium complex according to claim13 having formula (V):

wherein: X, Z, L, Y¹, R¹, R², R³, R⁴, R⁵ and R⁶ have the meaningreported in claims 6 or
 7. 17. A ligand of formula (II):

wherein X, Z, m, Y¹, Y², R¹, R², R³, R⁴, R⁵, R⁶, and R⁸ have the meaningreported in claim
 1. 18. The ligand according to claim 17 having formula(IIIa):

wherein X, Z, Y¹, R¹, R², R³, R⁴, R⁵, R⁶ and R⁸ have the meaningreported in claim 2 or
 3. 19. The ligand according to claim 17 havingformula (IVa):

wherein X, Z, Y¹, R¹, R⁴, R⁵, R⁶, R⁸, R⁹, and k have the meaningreported in claims 4 or
 5. 20. The ligand according to claim 17 havingformula (Va):

wherein X, Z, Y¹, R², R³, R⁴, R⁵, and R⁶have the meaning reported inclaims 6 or
 7. 21. A process for preparing the ligand of formula (II)

wherein X, Z, m, Y¹, Y², R¹, R², R³, R⁴, R⁵, R⁶, and R⁸ have the meaningreported in claim 1, comprising the following steps. i) reacting acompound of formula (VI):

wherein Y¹, m, R², R³, R⁴, R⁵, and R⁸ have the meaning reported above,with at least one equivalent of a base and then contacting the obtainedcompound with a compound of formula R¹ ₂ZY³Y⁴, wherein R¹ and Z have themeaning reported in claim 1, Y³ is a halogen atom and Y⁴ is an halogenatom or a group R⁶XH wherein R⁶ and X have the meaning reported in claim1 and H is hydrogen; ii) if Y⁴ is an halogen atom, reacting the obtainedproduct with a compound of formula R⁶XH₂ wherein R⁶ and X have themeaning reported in claim 1 and H is hydrogen, and recovering theproduct.
 22. A process for preparing the titanium complexes of formula(I) as described in claim 1 comprising: reacting a ligand of formula(II) as described in claim 17 with a compound able to form a delocalizeddianion on the cyclopentadienyl ring and on the group X as described inclaim 1, and thereafter with a compound of formula TiL′₄, wherein thesubstituents L′ are halogen or -OR, wherein R has the meaning reportedin claim 1.